@article{molina_soneja_diaz_tilotta_kelley_2022, title={At-Line Sampling and Characterization of Pyrolytic Vapors from Biomass Feedstock Blends Using SPME-GC/MS-PCA: Influence of Char on Fast Pyrolysis}, volume={12}, ISSN={["1520-5118"]}, DOI={10.1021/acs.jafc.2c06043}, abstractNote={Solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) analysis was used for the at-line sampling of pyrolytic vapors produced during the fast pyrolysis of biomass. The pure and binary blends of switchgrass (SWG) and pine harvest residues (PT6) were used as biomass feedstocks. Sequential SPME sampling allowed for monitoring of changes in the pyrolysis vapors as char accumulated in the fluid bed. The relative concentration and composition of the pyrolysis vapors desorbed from the SPME fibers were investigated using GC-MS, and the resulting chromatograms were analyzed using principal component analysis (PCA) to compare the composition of the pyrolysis vapors over the course of the pyrolysis run. The chemical compositions of both carbohydrate and lignin fragments varied as the char builds up in the reactor bed. Fragments derived from cellulose and hemicelluloses included anhydrosugars, furans, and light-oxygenated compounds. Lignin fragments included methoxyphenols, phenolic ketones, aldehydes, and low-molecular-weight aromatics. The composition of the carbohydrate fragments changed more than those of the lignin fragments as the char built up in the fluid bed. This combination of SPME-GC/MS-PCA was a novel, easy, and effective method for measuring the composition and changes in the composition of pyrolysis vapors during the fast pyrolysis process. This work also highlighted the effect of char build-up on the composition of the overall pyrolysis vapors.}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Molina, Eliezer A. Reyes and Soneja, Ravi and Diaz, Maria Herrera and Tilotta, David C. and Kelley, Stephen S.}, year={2022}, month={Dec} }
 @article{thomas_tilotta_frampton_jetton_2022, title={Sesquiterpene Induction by the Balsam Woolly Adelgid (Adelges piceae) in Putatively Resistant Fraser Fir (Abies fraseri)}, volume={13}, ISSN={["1999-4907"]}, DOI={10.3390/f13050716}, abstractNote={Fraser fir, Abies fraseri (Pursh) Poir., is a tree endemic to the Southern Appalachians and is found only in a few isolated populations at high elevations. Fraser firs are also cultivated on a commercial scale as Christmas trees. The species is imperiled by an introduced insect, the balsam woolly adelgid, Adelges piceae Ratzeburg (BWA). The insect severely damages Christmas tree crops and has caused substantial Fraser fir mortality in natural stands. Foliar terpenoids are one mechanism of host plant defense against invading insects and may be one focus of future Christmas tree breeding efforts. This study examines the correlation of foliar terpenoids with Fraser fir performance when infested with BWA. GC-MS and GC-FID analysis of artificially infested Fraser fir foliage reveals that increased concentrations of four terpenoid compounds are associated with BWA infestations. Foliar concentrations of two sesquiterpenes, camphene and humulene, are significantly higher in putatively resistant Fraser fir clones than in more susceptible clones after sustained adelgid feeding for a period of 20 weeks. Although it is unclear if the induction of these sesquiterpenes in the host fir is directly contributing to adelgid resistance, these compounds could serve as effective indicators while screening for BWA resistance in future Christmas tree breeding programs.}, number={5}, journal={FORESTS}, author={Thomas, Austin and Tilotta, David C. and Frampton, John and Jetton, Robert M.}, year={2022}, month={May} }
 @article{strayhorn_mitchell_tilotta_2022, title={Strength Properties of Full-Size Oriented Strand Board Panels Following Submergence in Potable and Salt Water}, volume={72}, ISSN={["0015-7473"]}, DOI={10.13073/FPJ-D-21-00058}, abstractNote={Abstract}, number={1}, journal={FOREST PRODUCTS JOURNAL}, author={Strayhorn, Tyler and Mitchell, Phil and Tilotta, David}, year={2022}, pages={58–66} }
 @article{laleicke_tilotta_mitchell_byington_2021, title={Evaluation of Low-Cost Moisture Meters for Wood}, volume={49}, ISSN={["1945-7553"]}, DOI={10.1520/JTE20190241}, abstractNote={Abstract}, number={5}, journal={JOURNAL OF TESTING AND EVALUATION}, author={Laleicke, Paul Frederik and Tilotta, David C. and Mitchell, Phil H. and Byington, Matthew}, year={2021}, month={Sep}, pages={3333–3343} }
 @article{kravetz_leca_brito_saloni_tilotta_2020, title={Characterization of Selected Pyrolysis Products of Diseased Orange Wood}, volume={15}, ISSN={["1930-2126"]}, DOI={10.15376/biores.15.3.7118-7126}, abstractNote={Orange trees in Brazil are often burned as a means of eradication when they become infected with Huanglongbing disease. Rather than destroying them, which is a low-value proposition, one potential option is to utilize the biomass through pyrolysis. In this preliminary work, orange trees (Citrus sinensis) otherwise selected for purging, were sampled and pyrolyzed at 500 °C, and the charcoal and bio-oil were evaluated for potential value-added use. The results showed that the pyrolysis process resulted in 26.3% charcoal, 57.6% bio-oil, and 16.0% non-condensable gases. Qualitative analysis of the bio-oil by gas chromatography/mass spectrometry found 178 chemical compounds; however, only 25% of those compounds could be reliably identified. Potential applications of the compounds identified in the bio-oil were determined by examining the published literature, and it was found that at least 73% of them showed promise. Finally, initial studies on the immediate analysis of the pyrolysis charcoal showed that it potentially meets the standards set forth for Brazilian domestic use.}, number={3}, journal={BIORESOURCES}, author={Kravetz, Carolina and Leca, Carlos and Brito, Jose Otavio and Saloni, Daniel and Tilotta, David C.}, year={2020}, month={Aug}, pages={7118–7126} }
 @article{adebawo_sadeghifar_tilotta_jameel_liu_lucia_2019, title={Spectroscopic Interrogation of the Acetylation Selectivity of Hardwood Biopolymers}, volume={71}, ISSN={["1521-379X"]}, DOI={10.1002/star.201900086}, abstractNote={Abstract}, number={11-12}, journal={STARCH-STARKE}, author={Adebawo, Funke and Sadeghifar, Hassan and Tilotta, David and Jameel, Hasan and Liu, Yu and Lucia, Lucian}, year={2019}, month={Nov} }
 @article{yoo_kelley_tilotta_park_2018, title={Structural Characterization of Loblolly Pine Derived Biochar by X-ray Diffraction and Electron Energy Loss Spectroscopy}, volume={6}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/ACSSUSCHEMENG.7B04119}, DOI={10.1021/acssuschemeng.7b04119}, abstractNote={Biochar from lignocellulosic biomass is emerging as a sustainable material with versatile applications, but its detailed properties are poorly understood because of its structural complexity. We propose a biochar structural development model based on experimental results including composition analysis, surface area and pore analysis, X-ray diffraction analysis, electron microscopy imaging, and electron energy loss spectroscopy. Loblolly pine derived biochars were produced at different carbonization temperatures between 300 to 1000 °C. Fixed carbon, sp2 content, and number of graphene layers increased with increased carbonization temperature. Alternating average C–C bond length, interlayer spacing distance, and layer coherence length were observed. Bulk plasmon excitation energy was correlated to the average C–C bond length, and it serves as a good indicator of the carbon structure development when compared to the perfect graphitic carbon structure. On the basis of the experimental results, four different ...}, number={2}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Yoo, Seunghyun and Kelley, Stephen S. and Tilotta, David C. and Park, Sunkyu}, year={2018}, month={Jan}, pages={2621–2629} }
 @article{bucholz_frampton_jetton_tilotta_lucia_2017, title={Effect of different headspace concentrations of bornyl acetate on fecundity ofgreen peach aphid and balsam woolly adelgid}, volume={32}, ISSN={["1651-1891"]}, DOI={10.1080/02827581.2016.1275769}, abstractNote={ABSTRACT Balsam woolly adelgid (Adelges piceae) (Hemiptera: Adelgidae) (BWA) is an exotic pest introduced from Europe to North America in the early 1900s. Subsequent introductions and spread have enabled this pest to infest native Fraser fir stands in the Southern Appalachians and become a troublesome pest for the region’s Christmas tree industry. Means to study its fecundity and control it are consequently of high importance. Headspace solid phase micro-extraction coupled with gas chromatography and mass spectrometry were used to compare chemical differences in stem tissue between a resistant species, Veitch fir (Abies veitchii) and the susceptible Fraser fir (Abies fraseri). Comparisons demonstrated that bornyl acetate (BA), a terpenoid, was qualitatively more abundant in resistant Veitch fir than Fraser fir. Varying headspace concentrations of BA were tested to ascertain any biological impacts on egg eclosion of BWA, as well as fecundity of green peach aphid (Myzus persicae) (GPA), an insect serving as a proxy. Varying concentrations of BA and a known number of adelgid eggs did not indicate any impact of concentration on egg eclosion success. However, defoliated Veitch fir branches in treatment jars produced a significant negative impact on BWA eclosion success. Implications of these findings are discussed.}, number={5}, journal={SCANDINAVIAN JOURNAL OF FOREST RESEARCH}, author={Bucholz, Ethan and Frampton, John and Jetton, Robert and Tilotta, David and Lucia, Lucian}, year={2017}, pages={397–405} }
 @article{kravetz_brito_saloni_tilotta_2017, title={Qualitative analysis of the extractives of orange wood}, volume={49}, number={4}, journal={Wood and Fiber Science}, author={Kravetz, C. and Brito, J. O. and Saloni, D. and Tilotta, D. C.}, year={2017}, pages={407–12} }
 @article{adebawo_naithani_sadeghifar_tilotta_lucia_jameel_ogunsanwo_2016, title={Morphological and interfacial properties of chemically-modified tropical hardwood}, volume={6}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/C5RA19409A}, DOI={10.1039/C5RA19409A}, abstractNote={Chemical esterification of wood biopolymers using acetic acid is a green method to sustain and improve the physical properties of native tropical hardwoods in part by drastically reducing the surface energy.}, number={8}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Adebawo, F. G. and Naithani, V. and Sadeghifar, Hasan and Tilotta, D. and Lucia, L. A. and Jameel, Hasan and Ogunsanwo, O. Y.}, year={2016}, pages={6571–6576} }
 @article{meng_moore_tilotta_kelley_adhikari_parkt_2015, title={Thermal and Storage Stability of Bio-Oil from Pyrolysis of Torrefied Wood}, volume={29}, ISSN={["1520-5029"]}, DOI={10.1021/acs.energyfuels.5b00929}, abstractNote={The objective of this paper is to investigate the biomass torrefaction effect on bio-oil stability by comparing the physicochemical and compositional properties of aged bio-oils. Two aging methods, accelerated aging (held at 80 °C for 24 h) and long-term natural aging (12-month storage at 25 °C), were employed to produce aged bio-oils for such comparison. The results indicate that bio-oils made from heat-treated wood had similar aging behavior in terms of increase of water content, acid content, molecular weight, and viscosity. The increase rate, however, was found to be different and dependent on the aging method. The accelerated method found parallel water and total acidity number (TAN) increments between raw and torrefaction bio-oils, while the natural aging method found torrefaction bio-oils, especially those made from heavily treated wood, had much slower water and acid accumulation than that of raw bio-oil. As a negative effect, both methods identified the viscosity of torrefaction bio-oils increase...}, number={8}, journal={ENERGY & FUELS}, author={Meng, Jiajia and Moore, Andrew and Tilotta, David C. and Kelley, Stephen S. and Adhikari, Sushil and Parkt, Sunkyu}, year={2015}, month={Aug}, pages={5117–5126} }
 @article{meng_smirnova_song_moore_ren_kelley_park_tilotta_2014, title={Identification of free radicals in pyrolysis oil and their impact on bio-oil stability}, volume={4}, ISSN={["2046-2069"]}, DOI={10.1039/c4ra02007c}, abstractNote={The existence of radicals in pyrolysis oil generated from loblolly pine in three different reactor systems was verified with electron paramagnetic resonance (EPR) spectroscopy.}, number={56}, journal={RSC ADVANCES}, author={Meng, Jiajia and Smirnova, Tatyana I. and Song, Xiao and Moore, Andrew and Ren, Xueyong and Kelley, Stephen and Park, Sunkyu and Tilotta, David}, year={2014}, pages={29840–29846} }
 @article{meng_moore_tilotta_kelley_park_2014, title={Toward Understanding of Bio-Oil Aging: Accelerated Aging of Bio-Oil Fractions}, volume={2}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/sc500223e}, DOI={10.1021/sc500223e}, abstractNote={Pyrolysis bio-oil from biomass is a promising intermediate for producing transportation fuels and platform chemicals. However, its instability, often called aging, has been identified as a critical hurdle that prevents bio-oil from being commercialized. The objective of this research is to explore the bio-oil aging mechanism by an accelerated aging test of fractionated bio-oil produced from loblolly pine. When water soluble (WS), ether insoluble (EIS), and pyrolytic lignin (PL) fractions were aged separately, the increased molecular weight (Mw) was observed with increasing aging temperature and the presence of acids. WS and EIS fractions had high Mw brown solids formed after aging. Adjusting the pH of WS and EIS fractions from 2.5 to 7.0 significantly reduced the tendency of a Mw increase. Similar Mw rise was also observed on a PL fraction with an elevated temperature and acid addition. Formaldehyde was found to react with the PL fraction in the presence of any acid catalysts tested, i.e., 8-fold Mw incre...}, number={8}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Meng, Jiajia and Moore, Andrew and Tilotta, David and Kelley, Stephen and Park, Sunkyu}, year={2014}, month={Jul}, pages={2011–2018} }
 @article{a concept for a performance‐based rating system for home resilience: rescu_2012, url={http://dx.doi.org/10.1108/17595901211245242}, DOI={10.1108/17595901211245242}, abstractNote={PurposeCitizens who live in disaster prone areas need to protect their properties – particularly their homes – against the destructive effects of natural disasters to avoid large‐scale economic losses. The purpose of this paper is to present the basic concepts and methodology for an improved system for rating the resilience of homes against natural disaster perils. This system is referred to as the Resilient Scoring Utility (ReScU) framework.}, journal={International Journal of Disaster Resilience in the Built Environment}, year={2012}, month={Jul} }
 @article{strayhorn_dasmohapatra_tilotta_mitchell_2012, title={Effectiveness of educational tools for hurricane resilience in homes}, volume={21}, ISSN={["0965-3562"]}, DOI={10.1108/09653561211256143}, abstractNote={PurposeIn the disaster mitigation community, one of the most important tasks is that of information transfer prior to, and following natural disasters. The purpose of this research project was to increase the understanding of key aspects (such as attractiveness and educational value) that influence the utility and effectiveness of educational media tools for home resilience during hurricanes.}, number={4}, journal={DISASTER PREVENTION AND MANAGEMENT}, author={Strayhorn, Tyler and Dasmohapatra, Sudipta and Tilotta, Dave and Mitchell, Phil}, year={2012}, pages={433–444} }
 @article{meng_park_tilotta_park_2012, title={The effect of torrefaction on the chemistry of fast-pyrolysis bio-oil}, volume={111}, ISSN={["0960-8524"]}, DOI={10.1016/j.biortech.2012.01.159}, abstractNote={Fast pyrolysis was performed on torrefied loblolly pine and the collected bio-oils were analyzed to compare the effect of the torrefaction treatment on their quality. The results of the analyses show that bio-oils produced from torrefied wood have improved oxygen-to-carbon ratios compared to those from the original wood with the penalty of a decrease in bio-oil yield. The extent of this improvement depends on the torrefaction severity. Based on the GC/MS analysis of the pyrolysis bio-oils, bio-oils produced from torrefied biomass show different compositions compared to that from the original wood. Specifically, the former becomes more concentrated in pyrolytic lignin with less water content than the latter. It was considered that torrefaction could be a potential upgrading method to improve the quality of bio-oil, which might be a useful feedstock for phenolic-based chemicals.}, journal={BIORESOURCE TECHNOLOGY}, author={Meng, Jiajia and Park, Junyeong and Tilotta, David and Park, Sunkyu}, year={2012}, month={May}, pages={439–446} }
 @book{chemical yields from low temperature pyrolysis of cca treated wood_2009, journal={USDA Forest Service}, year={2009} }
 @book{assessment of research and technology transfer needs for wood frame housing_2008, journal={USDA Forest Service}, year={2008}, month={Apr} }
 @article{fu_argyropoulos_tilotta_lucia_2008, title={Understanding the pyrolysis of CCA-treated wood Part I. Effect of metal ions}, volume={81}, ISSN={["1873-250X"]}, DOI={10.1016/j.jaap.2007.08.003}, abstractNote={The influence of several inorganic compounds (K2Cr2O7, CrO3 and CuSO4) on the pyrolysis of southern pine wood has been investigated. The wood powder was pre-treated with various inorganic compound solutions prior to the pyrolysis and the distribution and yields of the pyrolysis products were obtained by gas chromatography and quantitative 31P nuclear magnetic resonance (NMR) analyses. Our experiments showed that K2Cr2O7 and CuSO4 salts promoted the formation of levoglucosan (LG). In particular, the former providing higher LG yields up to 26.7%. The CrO3 treatment induced the production of low tar and high char yields, with a very low yield of LG and high yield of levoglucosenone (LGO). The underlying reasoning behind these findings may be due to an acidic catalysis mechanism, which promotes cellulose depolymerization and dehydration processes. Due to acid-catalyzed lignin condensation reactions, the yield of lignin degradation products from the pyrolysis of pre-treated wood was found to dramatically decrease in comparison to untreated wood.}, number={1}, journal={JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS}, author={Fu, Qirong and Argyropoulos, Dimitris S. and Tilotta, David C. and Lucia, Lucian A.}, year={2008}, month={Jan}, pages={60–64} }
 @article{fu_argyropoulos_tilotta_lucia_2008, title={Understanding the pyrolysis of CCA-treated wood. Part II. Effect of phosphoric acid}, volume={82}, ISSN={["1873-250X"]}, DOI={10.1016/j.jaap.2008.02.007}, abstractNote={The pyrolysis process of chromated copper arsenate-treated wood impregnated with phosphoric acid (2–6 wt.%) has been investigated using a Kugelrohr short-path distillation apparatus. The presence of phosphoric acid is shown to change the overall pyrolysis kinetics and yields of products resulting in a decrease in the amount of volatile products and an increase in the char formation. The yield of levoglucosan was found to decrease in the presence of relatively higher concentrations of phosphoric acid, while the yield of levoglucosenone increased. The pyrolysis of chromated copper arsenate-treated wood in the presence of phosphoric acid gave rise to 22% (on water-free tar basis) levoglucosenone. Such data demonstrates the potential for a new pathway toward the rational utilization of chromated copper arsenate-treated wood waste.}, number={1}, journal={JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS}, author={Fu, Qirong and Argyropoulos, Dimitris S. and Tilotta, David C. and Lucia, Lucian A.}, year={2008}, month={May}, pages={140–144} }
 @article{north carolina home building: a survey of people, practices and perceptions_2007, volume={9}, journal={North Carolina Builder}, year={2007}, pages={33–34} }
 @article{fu_argyropoulos_tilotta_lucia_2007, title={Products and functional group distributions in pyrolysis oil of chromated copper arsenate (CCA)-Treated wood, as elucidated by gas chromatography and a novel P-31 NMR-Based method}, volume={46}, ISSN={["0888-5885"]}, DOI={10.1021/ie0702274}, abstractNote={Low-temperature pyrolysis offers a feasible option for wood waste management and the recovery of a variety of useful chemicals. In this study, the effect of chromated copper arsenate (CCA) wood preservatives on the yield and composition of various pyrolysis products was investigated over the temperature range of 275−350 °C. For this preliminary work, we examined the feasibility of using gas chromatography coupled with either flame ionization detection or mass spectroscopic detection and a novel 31P nuclear magnetic resonance (NMR) spectroscopic method. Both methods worked well, with the gas chromatographic method being compound-specific and the 31P NMR method being specific to the functional group (e.g., aliphatic alcohols, total phenols, and carboxylic acids). The present experiments showed that the CCA treatment on wood had a significant effect on the amount of main carbohydrate degradation products of tar. The yield of levoglucosan (LG) from CCA-treated wood increased, while the yields of hydroxyacetal...}, number={16}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Fu, Qirong and Argyropoulos, Dimitris S. and Tilotta, David C. and Lucia, Lucian A.}, year={2007}, month={Aug}, pages={5258–5264} }
 @article{determination of total petroleum hydrocarbons in soil by dynamic on-line supercritical fluid extraction with infrared photometric detection._2003, url={https://doi.org/10.1016/s0021-9673(02)01917-9}, DOI={10.1016/s0021-9673(02)01917-9}, abstractNote={Total petroleum hydrocarbons (TPHs) in soil are determined by on-line dynamic supercritical fluid extraction (SFE) using infrared filter photometry detection. The filter photometer was constructed in the laboratory using a tungsten lamp, an optical notch filter that selects the C-H stretching vibration of the extracted organics, an optical chopper with demodulation electronics, and a PbSe detector. A modified high-pressure fiber optic flow cell was used to couple the SFE system to the photometer. Quantitation of TPHs was accomplished through the construction of calibration curves of integrated absorbance of C-H stretching (over time) versus concentration. Our studies show that the sensitivity of this system is affected by both the optical path length in the high-pressure cell and the SFE fluid flow-rate, and detection limits for TPHs are in the mid part-per-million range. The results of the application of this on-line SFE-IR instrument to the determination of TPHs in real-world samples show good agreement with those obtained from standard Soxhlet extraction-IR methods.}, journal={Journal of chromatography. A}, year={2003}, month={Feb} }
 @article{screening method for nitroaromatic compounds in water based on solid-phase microextraction and infrared spectroscopy._2001, url={https://doi.org/10.1021/es010550c}, DOI={10.1021/es010550c}, abstractNote={A new method is described for determining nitroaromatic compounds in water that combines solid-phase microextraction (SPME) and infrared (IR) spectroscopy. In this method, the compounds are extracted from a 250-mL volume of water into a small square (3.2 cm x 3.2 cm x 61.2 microm thick) of silicone polycarbonate copolymer film (MEM-213). Five nitroaromatic compounds, including 2,4,6-trinitrotoluene (TNT), were chosen to evaluate the SPME/IR procedure. Quantitation limits for the five test compounds range from 50 microg/L for TNT to 400 microg/L for nitrobenzene. Precision values, determined at aqueous concentrations of four times the quantitation limit, range from 4 to 7%, and linear dynamic ranges extend to the maximum limit of the IR instrumentation. The potential of this SPME/IR method for determining nitroaromatics in natural water samples was also investigated by extracting "real world" soil samples contaminated with TNT. Results obtained from the SPME/ IR determination of the diluted extracts were in reasonable agreement with those obtained from dichloromethane extraction followed by gas chromatographic analysis.}, journal={Environmental science & technology}, year={2001}, month={Sep} }
 @article{jager_mcclintic_tilotta_2000, title={Measurement of Petroleum Fuel Contamination in Water by Solid-Phase Microextraction with Direct Raman Spectroscopic Detection}, volume={54}, url={http://dx.doi.org/10.1366/0003702001948637}, DOI={10.1366/0003702001948637}, abstractNote={ A method is described for determining petroleum fuel contamination in water based on solid-phase microextraction and Raman spectroscopy (SPME/Raman). In this method, contaminants are extracted from aqueous solutions into a solid phase and then detected directly by using spontaneous Raman spectroscopy. The solid phase consists of a small volume (∼ 20 μL) of poly(dimethylsiloxane) that has an optical window in the 830–1600 cm−1 Raman shift region. This region is suitable for determining both aromatic and aliphatic fuel components. Four “real world” fuels—aviation gasoline, unleaded gasoline, jet fuel A, and #1 fuel oil—were used to test this new method. As shown, the SPME/Raman determinations performed in the visible spectral region were not adversely affected from the fluorescence of the marker dyes in these fuels. The linear dynamic ranges for the determinations exceeded the water solubility limits and spanned 1–3 orders of magnitude. The limits of detection with the use of the most sensitive Raman bands in each fuel were in the 8–12 ppm range with the exception of #1 fuel oil (25 ppm), and relative standard deviations typically were 2–10%. Finally, the SPME/Raman method was applied to the determination of total petroleum hydrocarbons in natural water matrices. With the use of hexane and undecane as standards, the results of the determinations compared favorably to the standard methods of purge-and-trap gas chromatography and liquid-liquid extraction followed by infrared detection. }, number={11}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Jager, Michael J. and McClintic, Daniel P. and Tilotta, David C.}, year={2000}, month={Nov}, pages={1617–1623} }
 @article{stahl_tilotta_1999, title={Partition Infrared Method for Total Gasoline Range Organics in Water Based on Solid Phase Microextraction}, volume={33}, url={http://dx.doi.org/10.1021/es980777g}, DOI={10.1021/es980777g}, abstractNote={A new method is described for determining total gasoline-range organics (TGRO) in water that combines solid-phase microextraction (SPME) and infrared (IR) spectroscopy. In this method, the organic compounds are extracted from 250-mL of water into a small square (3.2 cm × 3.2 cm × 130 μm thick) of Teflon PFA film. This film, a perfluoroalkoxyethylene polymer, lacks C−H bonds and makes it possible to quantitate the extracted organics directly in it via their C−H stretching vibrations. Three gasoline-range fuels, unleaded gasoline, aviation gas, and lighter fuel (petroleum naphtha), were chosen to evaluate the SPME/IR procedure. Preliminary experiments show that method detection limits are in the 0.5−1.5 ppm range for spiked solutions, and precision is relatively good (6−11% RSDs). Linear dynamic ranges of calibration extend to the water solubility limits for all fuels studied. Finally, the potential of this SPME/IR method for determining TGRO in natural “real world” water samples was investigated by extract...}, number={5}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Stahl, Danese C. and Tilotta, David C.}, year={1999}, month={Mar}, pages={814–819} }
 @article{extraction of petroleum hydrocarbons from soil using supercritical argon._1998, url={https://doi.org/10.1021/ac970983r}, DOI={10.1021/ac970983r}, abstractNote={The use of supercritical argon is described for the extraction of petroleum hydrocarbons from soil samples. Argon is an attractive solvent because it is inexpensive and inert. Additionally, it has a clear spectral window in the infrared region which makes it useful for on-line (i.e., directly coupled) experiments. Spiking studies conducted with gasoline, no. 1 fuel oil, and no. 5 fuel oil on sand, loam, and clay show that component recovery rates for argon supercritical fluid extraction (SFE) generally increase with increasing pressure and/or temperature. The highest recovery rates (and recoveries) were obtained for Ar SFE at 500 atm and 150 °C. Under these conditions, the components of the gasoline and no. 1 fuel oil spikes could be recovered in as little as 12 min. However, the no. 5 fuel oil components could not be quantitatively removed from the loam and clay matrixes even for extraction times as long as 100 min. We also show in this work that Ar SFE performs similarly to CO(2) SFE for petroleum hydrocarbon contamination in real-world soil samples under moderate pressure and temperature conditions. Specifically, Ar SFE and CO(2) SFE have similar recoveries and reproducibilities, but Ar SFE requires a slightly longer extraction time.}, journal={Analytical chemistry}, year={1998}, month={Feb} }
 @article{merschman_tilotta_1998, title={Fiber-Optic Sensor for Aromatic Compounds in Water Based on Solid-Phase Microextraction and Ultraviolet Evanescent Wave Absorption Spectroscopy}, volume={52}, url={http://dx.doi.org/10.1366/0003702981942401}, DOI={10.1366/0003702981942401}, abstractNote={ A method is described for the determination of aromatic contaminants in water samples that combines solid-phase microextraction and ultraviolet evanescent wave absorption (UV-EWA) spectroscopy. In this method, the aromatic compounds are partitioned from a 10 mL sample of water into the polymer cladding of a 10 cm length of UV-transmitting fiber. The aromatics are then detected directly in the cladding by EWA spectroscopy. The time required for four BTEX compounds to reach concentration equilibrium between the aqueous phase and the cladding ranges from 12 to 80 min, although we show that quantitative determinations can be accomplished in 30 min. Detection limits for these compounds range from 1 to 18 ppm, with relative standard deviations from 3 to 17%. Finally, preliminary work demonstrates that natural water matrices pose no significant matrix effects and that this method shows promise in determining the total aromatic concentrations of water samples contaminated with gasoline. }, number={1}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Merschman, Sheila A. and Tilotta, David C.}, year={1998}, month={Jan}, pages={106–111} }
 @article{on-line nonmetal detection for argon supercritical fluid extraction using inductively coupled plasma optical emission spectroscopy._1998, url={https://doi.org/10.1021/ac980420v}, DOI={10.1021/ac980420v}, abstractNote={This paper describes the development of a solventless instrumental method for determining organic contaminants in soil by coupling argon supercritical fluid extraction (SFE) to inductively coupled plasma atomic emission spectroscopy (ICP-AES). In this method, organic compounds are first extracted by Ar SFE, transferred to the ICP directly in the supercritical (SC) argon, fragmented in the plasma, and then determined via their nonmetal atomic emissions. Supercritical Ar is superior to SC CO(2) for use in ICP-AES because it overcomes the disadvantages of plasma blowout, noisy baselines, and CO(2) interference in the determination of carbon. All instruments employed were commercially available, and the interface between the SFE and the torch of the ICP consisted of a simple glass capillary tube. Four nonmetals, C, S, P, and Si, were selected for this preliminary study. The selectivities obtained for these nonmetals, referenced to carbon, were found to be 345, 38 000, and 1400 for sulfur, phosphorus, and silicon, respectively. With the exception of carbon, the mass detection limits are in the range of 0.06-1.8 μg. For this work, the mass detection limit of carbon is 66 μg and is limited by the smallest aliquot of material that can be injected by syringe. Finally, total petroleum hydrocarbons (TPHs) were determined in two "real world" contaminated soil samples via the carbon emission at 247.9 nm. Dodecane was used as the standard reference compound because its response was found to be similar to other petroleum hydrocarbons (e.g., kerosene, gasoline, no. 1 fuel oil, and no. 2 fuel oil). Additionally, it was found necessary to add a small amount (i.e., 250 mg) of drying agent to the SFE vessel in order to prevent the plasma from extinguishing from the extracted water. The results of the on-line Ar SFE/ICP-AES determinations of TPH in the two samples agreed well with those obtained from conventional off-line CO(2) SFE and off-line Ar SFE.}, journal={Analytical chemistry}, year={1998}, month={Nov} }
 @article{merschman_lubbad_tilotta_1998, title={Poly(dimethylsiloxane) films as sorbents for solid-phase microextraction coupled with infrared spectroscopy}, volume={829}, url={http://dx.doi.org/10.1016/s0021-9673(98)00800-0}, DOI={10.1016/s0021-9673(98)00800-0}, abstractNote={Poly(dimethylsiloxane) (PDMS) film was investigated as a stationary phase for solid-phase microextraction coupled with infrared (IR) spectroscopy. Five organic compounds of environmental concern (trichloroethylene, perchloroethylene, o-xylene, p-xylene, and trifluralin) were selected as test compounds for this study. Spiked solutions were extracted from 250-ml water samples into small squares (3.2×3.2 cm) of commercially available, 127-μm thick, PDMS film. The equilibration times for the test analytes in PDMS ranged from 60 to 85 min, and were about three times faster than those in Parafilm M. However, it was found that PDMS had poorer detection limits (in the range of 0.2–4.4 ppm) than those obtained with Parafilm M (in the range of 0.066–1.8 ppm). The relative standard deviations of the measurements were from 6.7–12%, and were governed primarily by volatility losses. Finally, preliminary work with PDMS demonstrates that real water matrices do not adversely affect the detection of organic compounds.}, number={1-2}, journal={Journal of Chromatography A}, publisher={Elsevier BV}, author={Merschman, Sheila A. and Lubbad, Said H. and Tilotta, David C.}, year={1998}, month={Dec}, pages={377–384} }
 @article{wittkamp_hawthorne_tilotta_1997, title={Determination of Aromatic Compounds in Water by Solid Phase Microextraction and Ultraviolet Absorption Spectroscopy. 1. Methodology}, volume={69}, url={http://dx.doi.org/10.1021/ac960761d}, DOI={10.1021/ac960761d}, abstractNote={A simple method is described for determining aromatic compounds (i.e., benzene, toluene, ethylbenzene, etc.) in water that combines solid phase microextraction (SPME) and ultraviolet (UV) absorption spectroscopy. The extraction medium consists of a small “chip” of poly(dimethylsiloxane) (total volume of ∼80 μL) that is immersed in a water sample contaminated with an aromatic compound. Equilibrium is first allowed to establish between the analyte in the water and the extraction medium, and the concentration of the aromatic compound is then determined directly in the sorbent chip by UV spectroscopy. Calibration information on this new method was obtained for 11 aromatic compounds commonly found in unleaded gasoline (e.g., benzene, toluene, naphthalene, etc). It was found that equilibrium is established in the range of 30−50 min, with the exception of 1-methylnaphthalene and naphthalene, which equilibrated within 100 min. Detection limits for the aromatic compounds at their equilibration times range from 0.4...}, number={6}, journal={Analytical Chemistry}, publisher={American Chemical Society (ACS)}, author={Wittkamp, Brian L. and Hawthorne, Steven B. and Tilotta, David C.}, year={1997}, month={Mar}, pages={1197–1203} }
 @article{wittkamp_hawthorne_tilotta_1997, title={Determination of Aromatic Compounds in Water by Solid Phase Microextraction and Ultraviolet Absorption Spectroscopy. 2. Application to Fuel Aromatics}, volume={69}, url={http://dx.doi.org/10.1021/ac9607626}, DOI={10.1021/ac9607626}, abstractNote={Solid phase microextraction is coupled with ultraviolet absorption spectroscopy to determine fuel aromatic hydrocarbons from unleaded gasoline, jet fuel (JP4), and no. 1 diesel fuel in water. A rectangular “chip” of poly(dimethylsiloxane) (OV-1) was used as the sorbent medium to selectively partition the various fuels from real water matrices without interferences from naturally occurring organics (e.g., humic and fulvic acids). Equilibration times are under 45 min for the majority of aromatic compounds and range from 150 to 300 min for the three fuels. However, it is shown that the fuels can be quantitated at significantly shorter extraction times (45 min), resulting in only a loss of ∼2× in the detection limits. Detection limits for unleaded gasoline, JP4, and no. 1 diesel fuel (obtained at their 100% equilibration times) are 4.9, 17, and 9.0 ppb, respectively. In addition, recovery data for the aromatic components from unleaded gasoline, JP4, and no. 1 diesel fuel from two real water matrices are in th...}, number={6}, journal={Analytical Chemistry}, publisher={American Chemical Society (ACS)}, author={Wittkamp, Brian L. and Hawthorne, Steven B. and Tilotta, David C.}, year={1997}, month={Mar}, pages={1204–1210} }
 @article{current_tilotta_1997, title={Determination of total petroleum hydrocarbons in soil by on-line supercritical fluid extraction-infrared spectroscopy using a fiber-optic transmission cell and a simple filter spectrometer}, volume={785}, url={http://dx.doi.org/10.1016/s0021-9673(97)00466-4}, DOI={10.1016/s0021-9673(97)00466-4}, abstractNote={An on-line supercritical fluid extraction-infrared (SFE-IR) instrument is described for determining total petroleum hydrocarbons (TPHs) in soil samples. This instrument is constructed from a commercially-available SFE system and filter IR spectrometer, and an easily-constructed fiber optic IR cell. All SFEs are performed statically (i.e., no fluid flow once the SFE vessel is filled) for 30 min at 80°C and 340 atm. Detection limits for TPH were determined to be ca. 8 ppm for an IR cell with a 1-mm optical path, and are shown to degrade with increasing pathlength. The results from the application of this on-line SFE-IR instrument to the determination of TPHs in real-world samples show good agreement with those obtained from a standard Soxhlet extraction-IR method. Relative standard deviations of the on-line determinations are in the range of 7–10%.}, number={1-2}, journal={Journal of Chromatography A}, publisher={Elsevier BV}, author={Current, Robert W. and Tilotta, David C.}, year={1997}, month={Oct}, pages={269–277} }
 @article{heglund_tilotta_1996, title={Determination of Volatile Organic Compounds in Water by Solid Phase Microextraction and Infrared Spectroscopy}, volume={30}, url={http://dx.doi.org/10.1021/es9504303}, DOI={10.1021/es9504303}, abstractNote={A simple method is described combining solid phase microextraction (SPME) and infrared (IR) spectroscopy for determining volatile organic compounds (VOCs) in water. The solid phase consists of a small square of Parafilm (130 μm thick) that is used to selectively extract the VOCs from the water. Infrared transmission spectroscopy is used to detect the extracted VOCs directly in the Parafilm. Ten VOCs (e.g., benzene, chlorobenzene, toluene, chloroform, and p-chlorotoluene) are chosen to evaluate the SPME-IR procedure. Preliminary experiments show that detection limits are in the 66 ppb−1.3 ppm range for spiked solutions, and linear dynamic calibration ranges extend nearly to the water solubility limits for all VOCs examined. Although the formal equilibration times are determined to be 30−200 min for these VOCs, we demonstrate that reproducible extractions can also be performed at 30 min. The application of SPME-IR to a real water sample shows no significant matrix interferences. Finally, the potential for d...}, number={4}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Heglund, Daniel L. and Tilotta, David C.}, year={1996}, month={Mar}, pages={1212–1219} }
 @article{tilotta_zhou_1995, title={Design and Performance of a Hadamard Transform Infrared Spectrometer with No Moving Parts}, volume={49}, url={http://dx.doi.org/10.1366/0003702953965218}, DOI={10.1366/0003702953965218}, abstractNote={ The development of an improved Hadamard transform infrared HT-IR) spectrometer with no moving optical parts is described. This spectrometer is based on a thermo-optic array for the stationary encoding of radiation (TOASTER) fabricated from Nichrome resistance wire. The TOASTER HT-IR instrument utilizes a reversed Czerny-Turner optical mount and relies on entrance focal plane modulation for operation. This design allows the dedispersion optics to be eliminated while still providing for a multiplex advantage. In addition, a conventional mechanical chopper is not needed in this instrument because the TOASTER is used as a natural modulator. The TOASTER HT-IR spectrometer can acquire an infrared spectrum in the range of 2.5 to 11 μm (4000 to 910 cm−1). Its spectral resolution is 0.07 μm (∼7 cm−1 at 1000 cm−1), and, for fifteen spectral resolution elements, the observation window is 0.5 μm (∼48 cm−1 at 1000 cm−1). In addition to the design of the instrument, this communication also examines the thermo-optic switching properties of the Nichrome wire used in the prototype TOASTER. Although the maximum switching speed of the Nichrome wire is governed by its thermal decay time, we show that the TOASTER can be operated faster than this limit by employing a preheating step. }, number={9}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Tilotta, David C. and Zhou, Zhou}, year={1995}, month={Sep}, pages={1338–1346} }
 @article{wittkamp_tilotta_1995, title={Determination of BTEX Compounds in Water by Solid-Phase Microextraction and Raman Spectroscopy}, volume={67}, url={http://dx.doi.org/10.1021/ac00099a018}, DOI={10.1021/ac00099a018}, abstractNote={A new method is described for determining benzene, toluene, ethylbenzene, and xylenes (BTEX) in water that combines solid-phase microextraction and spontaneous Raman spectroscopy. In this method, the BTEX analytes are extracted from the water solution into a solid phase before direct detection by Raman spectroscopy. The solid phase consists of a small volume (ca. 55 μL) of poly(dimethylsiloxane) itch has optical windows in the 750-1300- and 1410-2800-cm -1 Raman shift regions. The time required for each BTEX compound to reach equilibrium between the solid phase and the aqueous phase is in the rye of 16-30 min and affords preconcentration enhancements of 2-3 orders of magnitude. Limits of detection using the most intense Raman bands are in the 1-4-ppm range and produce relative standard deviations of 3-9%. Preliminary application of this new method to the detection of BTEX compounds in real-world water samples shows no significant interferences from river and well water matrices}, number={3}, journal={Analytical Chemistry}, publisher={American Chemical Society (ACS)}, author={Wittkamp, Brian L. and Tilotta, David C.}, year={1995}, month={Feb}, pages={600–605} }
 @article{wittkamp_tilotta_1994, title={Detection of alcohols in gas chromatographic effluent by laser-light scattering}, volume={670}, url={http://dx.doi.org/10.1016/0021-9673(94)80289-0}, DOI={10.1016/0021-9673(94)80289-0}, abstractNote={Abstract A laser-light-scattering detector that is sensitive to alcohols has been developed for gas chromatography. The detector consists of a miniature concentric nebulizer that uses a cold atomization gas and an Ar + laser. Calibration curves for the alcohols exhibit characteristic sigmoidal shapes. Signal-to-noise ratios were optimized by examining the photomultiplier tube temperature, collection wavelength and detection scheme ( i.e. , photon counting vs . direct current detection). Limits of detection for five test alcohols were in the 2–8 μg/s range.}, number={1-2}, journal={Journal of Chromatography A}, publisher={Elsevier BV}, author={Wittkamp, Brian L. and Tilotta, David C.}, year={1994}, month={Jun}, pages={145–152} }
 @article{nelson-avery_tilotta_1994, title={Near-Infrared Molecular Emission from a Gas Fountain}, volume={48}, url={http://dx.doi.org/10.1366/0003702944027895}, DOI={10.1366/0003702944027895}, abstractNote={ An electrothermal fountain is used to heat gas-phase samples in the range of 300 to 400°C in order to observe their near-infrared (NIR) emissions. In conjunction with the fountain, a 1/8-m Ebert monochromator and an uncooled PbS detector are shown to be sufficiently sensitive for recording the NIR fingerprints of CH4, CO2, N2O, and C2H6. At fountain temperatures of approximately 400°C, the molecular emission is confined to the long wavelength NIR region (1600–2500 nm) and yields limits of detection in the range of 4 to 10% v/v (3–10 mg/s). Reproducibilities have relative standard deviations of 3.0%. The calibration curves for the gases examined in this study have small linear dynamic ranges (factors of 2 to 10) and exhibit some degree of upward curvature. Ramifications of the application of NIR molecular emission spectroscopy to the qualitative and quantitative analyses of mixtures are discussed. }, number={12}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Nelson-Avery, Bonnie A. and Tilotta, David C.}, year={1994}, month={Dec}, pages={1461–1467} }
 @article{heglund_tilotta_hawthorne_miller_1994, title={Simple Fiber-Optic Interface for Online Supercritical Fluid Extraction Fourier Transform Infrared Spectrometry}, volume={66}, url={http://dx.doi.org/10.1021/ac00092a041}, DOI={10.1021/ac00092a041}, abstractNote={A simple and inexpensive fiber-optic interface for coupling a supercritical fluid extractor to a FT-IR spectrometer is described. The interface, based on chalcogenide (AsSeTe) fiber optics and a stainless steel union cross, is rugged up to pressures of 400 atm, has a spectral window from 5000 to 800 cm -1 , and is relatively easy to clean. It is shown that the SFE-FT-IR interface allows qualitative and quantitative information to be obtained from the extracts of real-world samples (caffeine in coffee and total petroleum hydrocarbons in soil, respectively) without the use of either a flow restrictor or a collection solvent}, number={20}, journal={Analytical Chemistry}, publisher={American Chemical Society (ACS)}, author={Heglund, Daniel L. and Tilotta, David C. and Hawthorne, Steven B. and Miller, David J.}, year={1994}, month={Oct}, pages={3543–3551} }
 @article{determination of chlorinated hydrocarbons introduced into air/acetylene flames by fourier transform infrared emission spectroscopy._1993, url={https://doi.org/10.1016/0039-9140(93)80330-t}, DOI={10.1016/0039-9140(93)80330-t}, abstractNote={A Fourier transform spectrometer is used to record the infrared emission from chlorinated hydrocarbons combusted in an air/acetylene flame. In this manner, the chlorinated hydrocarbons are determined by monitoring the infrared emission of hydrogen chloride at 2653 cm−1. Discussion is presented of the air/acetylene flame background, and the potential spectral interference from the emission of deuterated species. Practical detection limits for chloroform, carbon tetrachloride and methylene chloride in acetone, methanol, and ethanol are solvent independent and are found to be 1.1, 0.80, and 1.0%, respectively. Calibration curves for these three analytes are linear from their detection limits to approximately 55% (v/v). In addition, evidence is presented that flame flicker-noise does not lead to a multiplex disadvantage when the Fourier transform instrument is used for data acquisition.}, journal={Talanta}, year={1993}, month={Feb} }
 @article{tilotta_lam_busch_busch_1993, title={Evaluation of Thermospray and Cross-Flow Pneumatic Nebulization as Means of Interfacing a Flame Infrared Emission (FIRE) Radiometer to a High-Performance Liquid Chromatograph}, volume={47}, url={http://dx.doi.org/10.1366/0003702934048262}, DOI={10.1366/0003702934048262}, abstractNote={ A cross-flow pneumatic nebulizer and a thermospray nebulizer were each studied as a means of interfacing a flame infrared emission (FIRE) radiometer to a high-performance liquid chromatograph (HPLC). Both nebulizers introduced significant quantities of liquid mobile phase into the FIRE burner, necessitating modifications to the basic burner design and causing temperature changes in the hydrogen/air flame used as the FIRE source. Tailing in the trailing edge of the peak profiles was also observed with the use of pneumatic nebulization and attributed to dead volume present in the nebulizer spray chamber. Flame background caused by the combustion of carbon-containing mobile phases was also a problem, but could be avoided when the FIRE radiometer was operated in the carbon mode by using water as the mobile phase. Flame background from carbon-containing mobile phases could also be electronically subtracted by using a dual-channel, chlorine-specific FIRE radiometer to selectively determine mixtures of chlorinated hydrocarbons in the presence of a chlorine-free mobile phase. Background subtraction had the added advantage of improving the detection limits for organochlorine compounds by a factor of approximately 3. Detection limits for FIRE/HPLC using pneumatic nebulization and the single-channel FIRE radiometer in the carbon mode were estimated as 3.7 μg s−1 (5.5 × 102 μg) for acetic acid and 0.80 μg s−1 (1.2 × 102 μg) for ethanol with water as the mobile phase. FIRE/HPLC detection limits using thermospray nebulization and a dual-channel FIRE radiometer in the chlorine-specific mode were estimated as 6.2 μg s−1 (3.7 × 102 μg) for methylene chloride and 9.7 μg s−1 (5.8 × 102 μg) for carbon tetrachloride with a combustible mixture of 49% acetonitrile, 20% methanol, 30% water, and 1% acetic acid as the mobile phase. }, number={2}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Tilotta, David C. and Lam, Christopher K. Y. and Busch, Kenneth W. and Busch, Marianna A.}, year={1993}, month={Feb}, pages={192–200} }
 @article{tilotta_busch_busch_1991, title={A Miniature Electrical Furnace as an Excitation Source for Low-Temperature, Gas-Phase, Infrared Emission Spectroscopy}, volume={45}, url={http://dx.doi.org/10.1366/0003702914337579}, DOI={10.1366/0003702914337579}, abstractNote={ The analytical utility of low-temperature, gas-phase infrared emission spectroscopy is studied with the use of a specially designed miniature electrical furnace. This furnace, designed to minimize blackbody radiation from the source itself, was capable of operating between 100 and 1000°C and producing infrared emission from parent analyte molecules, as opposed to their terminal combustion products, such as CO2 and H2O. The low-temperature, infrared emission spectra of nitrous oxide (225°C) and methyl benzoate (250 and 700°C) are reported, and the feasibility of determining ethanol in gasohol is evaluated with the use of the alcohol C-O stretching vibration (observed at 1070 cm−1 in emission). The detection limit for ethanol in gasohol at 202°C was found to be 0.124% v/v, and the relative standard deviation of eight single-scan determinations of ethanol in a 10% v/v gasohol blend was found to be 4.01%. Some of the advantages and limitations associated with analytical, low-temperature, gas-phase, infrared emission spectroscopy are discussed and compared with results obtained with a hydrogen/air flame as the excitation source. }, number={2}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Tilotta, David C. and Busch, Marianna A. and Busch, Kenneth W.}, year={1991}, month={Feb}, pages={178–185} }
 @article{design and performance of a direct-reading, multichannel spectrometer for the determination of chlorinated purgeable organic compounds by flame infrared-emission spectrometry._1991, url={https://doi.org/10.1016/0039-9140(91)80141-l}, DOI={10.1016/0039-9140(91)80141-l}, abstractNote={The feasibility of determining chlorinated, purgeable organic compounds (POCs) in aqueous samples by flame infrared-emission (FIRE) spectrometry was evaluated with a specially designed, multichannel, dispersive spectrometer having sufficient resolving power to prevent interference from large amounts of non-halogenated POCs that could also be present in the sample. The polychromator was based on a Czerny—Turner optical mounting with a 0.15-m focal length, a nominal focal ratio of f/3, and a reciprocal linear dispersion of 0.15 μm/mm in the first order. The HCl and CO2 infrared emission bands (3.77 and 4.42 μm, respectively) were monitored in two analytical channels, while a third reference channel, used for background subtraction, monitored the H2O background emission at 2.8 μm. Instrumental performance was evaluated with dichloromethane, trichloromethane, trichloroethylene, 1,1,2,2-tetrachloroethane and monochlorobenzene as test compounds, and parameters such as the linear dynamic range, reproducibility, detection limit and signal-to-noise ratio, and extent of spectral crosstalk between channels were determined. The feasibility of performing a quantitative analysis of a two-component mixture of dichloromethane and trichloromethane at trace levels was demonstrated.}, journal={Talanta}, year={1991}, month={Jun} }
 @article{ravishankar_tilotta_busch_busch_1991, title={Spatial Emission Characteristics of a Capillary-Burner Excitation Source for a Flame Infrared Emission (FIRE) Radiometer}, volume={45}, url={http://dx.doi.org/10.1366/0003702914335102}, DOI={10.1366/0003702914335102}, abstractNote={ A complete mapping of the lateral and radial intensities of the 4.4- μm emission (antisymmetric CO2 stretch) resulting from the direct introduction of carbon dioxide, a homologous series of aliphatic hydrocarbons, and benzene into a hydrogen/air combustion flame supported on a capillary burner has been carried out. Both concentrated (99% methane, ethane, propane, and butane) and dilute (1% methane, ethane, propane, and benzene) hydrocarbons were studied. Flame profiles produced by the introduction of carbon dioxide were used to indicate the effects of local variations in source temperature and carbon dioxide number density in the absence of combustion. The radial profiles produced by the introduction of carbon dioxide and the hydrocarbons revealed a considerable amount of off-axis emission, believed to result from a zone of low temperature along the central vertical axis of the burner. Combustion of analyte appeared to be a diffusion-controlled process. For aliphatic hydrocarbons, combustion produced nearly quantitative amounts of carbon dioxide, provided the flame was not overloaded. For benzene, combustion produced particulate carbon, and the resulting blackbody emission was not strictly related to analyte concentration or carbon number. Blackbody emission may also result from the incomplete combustion of longer chain aliphatic hydrocarbons (propane and butane), if the burner is overloaded. }, number={10}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Ravishankar, S. and Tilotta, David C. and Busch, Kenneth W. and Busch, Marianna A.}, year={1991}, month={Dec}, pages={1684–1694} }
 @article{ravishankar_tilotta_busch_busch_1990, title={An Element-Specific, Dual-Channel, Flame Infrared Emission, Gas Chromatography Detector for Chlorinated and Fluorinated Hydrocarbons}, volume={44}, url={http://dx.doi.org/10.1366/000370290789619432}, DOI={10.1366/000370290789619432}, abstractNote={A flame infrared emission (FIRE) gas chromatography (GC) detector for organofluorine and organochlorine compounds has been developed and evaluated. The element-specific GC-FIRE detector makes use of a beamsplitter to divide the source radiation into two optical paths. The divided radiation passes through appropriate notch filters to isolate the background and analyte emission, which are each monitored by separate lead selenide detectors that form part of a Wheatstone bridge network. The output from the Wheatstone bridge is fed into the differential mode (A-B) input of a lock-in amplifier (LIA). In the chlorine mode of operation, a 3.7- μm optical notch filter is used in the analytical channel to isolate a portion of the HCl emission that results when organochlorine compounds are combusted in the hydrogen/air flame. In the fluorine mode of operation, a 2.35- μm optical notch filter in combination with a 2.55- μm short-pass filter is used to isolate a portion of the HF emission that results when organofluorine compounds are combusted. With the use of the dual-channel system, selectivity ratios of at least 760 (F) and 100 (Cl) were obtained, respresenting improvements by factors of about 104 (F) and 30 (Cl) in comparison with results from the single-channel mode of operation. With the use of Freon-113® (C2Cl3F3) as a representative analyte, detection limits in both the chlorine- and fluorine-selective modes were 200 ng s−1, representing improvements by factors of about 9.5 (F) and 4.5 (Cl), in comparison with results from the single-channel mode of operation.}, number={8}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Ravishankar, S. and Tilotta, David C. and Busch, Kenneth W. and Busch, Marianna A.}, year={1990}, month={Sep}, pages={1247–1258} }
 @article{lam_tilotta_busch_busch_1990, title={An Investigation of the Signal Obtained from a Flame Infrared Emission (FIRE) Detector}, volume={44}, url={http://dx.doi.org/10.1366/0003702904085705}, DOI={10.1366/0003702904085705}, abstractNote={ The effect of temperature on the atmospheric asymmetric stretching vibration of carbon dioxide is studied by flame/furnace infrared emission (FIRE) spectroscopy, and a mathematical expression is developed for the resulting infrared emission signal produced by the FIRE detector. This theoretical model, which can easily be extended to other species besides carbon dioxide, is used to calculate the signal obtained for propane when the FIRE system is used as a detector for gas chromatography. Comparison of the calculated (70 μV) and experimentally observed (75.8 μV) chromatographic signal shows that the theoretical model should be of great value in improving and optimizing the FIRE detector. }, number={2}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Lam, Christopher K. Y. and Tilotta, David C. and Busch, Kenneth W. and Busch, Marianna A.}, year={1990}, month={Feb}, pages={318–325} }
 @article{ravishankar_tilotta_kubala_busch_busch_1990, title={Dual-channel flame infrared emission detector for gas chromatography}, volume={62}, url={http://dx.doi.org/10.1021/ac00214a013}, DOI={10.1021/ac00214a013}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDual-channel flame infrared emission detector for gas chromatographyS. Ravishankar, D. C. Tilotta, S. W. Kubala, M. A. Busch, and K. W. BuschCite this: Anal. Chem. 1990, 62, 15, 1604–1610Publication Date (Print):August 1, 1990Publication History Published online1 May 2002Published inissue 1 August 1990https://doi.org/10.1021/ac00214a013RIGHTS & PERMISSIONSArticle Views54Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (3 MB) Get e-Alerts Get e-Alerts}, number={15}, journal={Analytical Chemistry}, publisher={American Chemical Society (ACS)}, author={Ravishankar, S. and Tilotta, D. C. and Kubala, S. W. and Busch, M. A. and Busch, K. W.}, year={1990}, month={Aug}, pages={1604–1610} }
 @article{tilotta_fry_fateley_1990, title={Selective multiplex advantage with an electro-optic Hadamard transform spectrometer for multielemental atomic emission.}, volume={37}, url={https://doi.org/10.1016/0039-9140(90)80046-i}, DOI={10.1016/0039-9140(90)80046-i}, abstractNote={A liquid-crystal spatial light-modulator Hadamard transform spectrometer is adapted for multielemental atomic spectrochemical analysis. The flame emissions of alkali metals are studied as a preliminary example. The multiplex disadvantage normally plaguing application of Hadamard and Fourier transform methods to atomic analysis is circumvented. Permanent electro-optic “closure” of certain Hadamard mask slits (corresponding to intense major element emissions) improves the signal-to-noise ratio (SNR) of the remaining trace element emissions. This approach to SNR enhancement of weaker spectral features by blocking known intense features is called the selective multiplex advantage. A problem with the contrast ratio (relative transmissions of the transparent and opaque states) of the liquid-crystal Hadamard mask has been identified in terms of “optical leakage”. This produces an offset in the Hadamard encodegram, and leads to concentration-dependent baseline-offset effects in the transformed spectrum. A mathematical correction procedure was devised and evaluated experimentally.}, number={1}, journal={Talanta}, publisher={Elsevier BV}, author={Tilotta, David C. and Fry, Robert C. and Fateley, William G.}, year={1990}, month={Jan}, pages={53–60} }
 @article{theoretical multiplex gain in a uv/vis hadamard transform spectrometer utilizing a uniformly imperfect encoding mask._1990, url={https://doi.org/10.1016/0039-9140(90)80047-j}, DOI={10.1016/0039-9140(90)80047-j}, abstractNote={The effect of a uniformly imperfect (non-ideal) encoding mask on the signal-to-noise ratio improvement in a Hadamard transform spectrometer utilizing photon detection is theoretically studied. General equations are developed for the calculation of the multiplex gain (the Fellgett advantage) under conditions of limitation by shot noise and source-fluctuation noise. It is shown that for both cases, the multiplex gain depends on the transmission properties of the encoding mask, the UV/VIS spectrum impinging upon the mask, and the multiplex size, N. It is demonstrated that a uniformly imperfect encoding mask allows sufficient multiplex gain, and that photon-detection in Hadamard transform spectrometry can have advantages in some spectroscopic applications. In addition, comparisons are made between the multiplex gain advantages present in UV/VIS FTS and those present in UV/VIS HTS.}, journal={Talanta}, year={1990}, month={Jan} }
 @article{kubala_tilotta_busch_busch_1989, title={Determination of chloride and available chlorine in aqueous samples by flame infrared emission}, volume={61}, url={http://dx.doi.org/10.1021/ac00199a020}, DOI={10.1021/ac00199a020}, abstractNote={Les ions chlorures et hypochlorites sont oxydes en chlore moleculaire par addition d'acide sulfurique concentre et de permanganate de potassium. Le chlore est extrait de la solution par un courant d'helium et entraine dans une flamme hydrogene/air. La lumiere emise est mesuree a 3150-2425 cm −1 par un detecteur PbSe. Les limites de detection sont de 1,59 ppm en Cl − et 1.61 ppm en Cl 2}, number={24}, journal={Analytical Chemistry}, publisher={American Chemical Society (ACS)}, author={Kubala, S. W. and Tilotta, D. C. and Busch, M. A. and Busch, K. W.}, year={1989}, month={Dec}, pages={2785–2791} }
 @article{kubala_tilotta_busch_busch_1989, title={Determination of total inorganic carbon in aqueous samples with a flame infrared emission detector}, volume={61}, url={http://dx.doi.org/10.1021/ac00192a012}, DOI={10.1021/ac00192a012}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of total inorganic carbon in aqueous samples with a flame infrared emission detectorS. Wayne. Kubala, David C. Tilotta, Marianna A. Busch, and Kenneth W. BuschCite this: Anal. Chem. 1989, 61, 17, 1841–1846Publication Date (Print):September 1, 1989Publication History Published online1 May 2002Published inissue 1 September 1989https://doi.org/10.1021/ac00192a012RIGHTS & PERMISSIONSArticle Views460Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts}, number={17}, journal={Analytical Chemistry}, publisher={American Chemical Society (ACS)}, author={Kubala, S. Wayne. and Tilotta, David C. and Busch, Marianna A. and Busch, Kenneth W.}, year={1989}, month={Sep}, pages={1841–1846} }
 @article{flame/furnace infrared emission spectroscopy:  new ways of playing with fire_1989, journal={Spectroscopy}, year={1989} }
 @article{tilotta_busch_busch_1989, title={Fourier Transform Flame Infrared Emission Spectroscopy}, volume={43}, url={http://dx.doi.org/10.1366/0003702894202454}, DOI={10.1366/0003702894202454}, abstractNote={ The thermal fragmentation of organic compounds in a hydrogen/air flame is studied via Fourier transform flame infrared emission (FT-FIRE) spectroscopy. In this preliminary survey of more than 75 organic compounds, it is shown that compound and element-specific infrared emission bands are produced when organic compounds containing C, H, Cl, F, S, and Si are combusted in the flame. Correlations of these infrared emission bands with possible combustion products are presented. }, number={4}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Tilotta, David C. and Busch, Kenneth W. and Busch, Marianna A.}, year={1989}, month={May}, pages={704–709} }
 @article{tilotta_hammaker_fateley_1987, title={A Visible Near-Infrared Hadamard Transform Spectrometer Based on a Liquid Crystal Spatial Light Modulator Array: A New Approach in Spectrometry}, volume={41}, url={http://dx.doi.org/10.1366/0003702874448300}, DOI={10.1366/0003702874448300}, abstractNote={ A stationary Hadamard encodement mask has been designed from a liquid crystal display. This mask, when properly installed and positioned in a dispersive instrument, allows the selected Hadamard encoded spectral elements to be focused on a single detector. Discussion of the advantages derived by this technique is presented. Several emission spectra in the visible and near-infrared region demonstrate the usefulness of the Hadamard transform technique. This novel spectrometer can provide a no-moving-parts spectroscopy for future spectral applications. }, number={5}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Tilotta, D. C. and Hammaker, R. M. and Fateley, W. G.}, year={1987}, month={Jul}, pages={727–734} }
 @article{hadamard transform spectrometry: teaching old monochromators new tricks_1987, journal={Spectroscopy}, year={1987} }
 @article{tilotta_freeman_fateley_1987, title={Hadamard Transform Visible Raman Spectrometry}, volume={41}, url={http://dx.doi.org/10.1366/0003702874447383}, DOI={10.1366/0003702874447383}, abstractNote={ The successful application of LC-SLM Hadamard transform spectrometry as a simultaneous multiwavelength detection system to Raman spectroscopy is presented. Multiplexed Raman data are obtained with the use of an Ar+ laser lasing at 514.5 nm and a room-temperature silicon photodiode. A conventional 90° scattering geometry is employed for measurements. It is demonstrated that the LC-SLM Hadamard transform Raman spectrometer possesses the capability of performing spectral subtraction and the ability to obtain depolarization ratios of Raman bands, and can function as a selectively tunable optical filter for both Rayleigh line rejection and optical band notching. It is also demonstrated that, for the Hadamard transform Raman experiment, the silicon photodiode used as the detector produces spectra with slightly better signal-to-noise ratios than those obtained with the photomultiplier tube (PMT) used as the detector, although the PMT shows an increase in sensitivity. }, number={8}, journal={Applied Spectroscopy}, publisher={SAGE Publications}, author={Tilotta, David C. and Freeman, Robert D. and Fateley, William G.}, year={1987}, month={Nov}, pages={1280–1287} }
 @article{multiplex advantage in hadamard transform spectrometry utilizing solid-state encoding masks with uniform, bistable optical transmission defects._1987, url={https://doi.org/10.1364/AO.26.004285}, DOI={10.1364/ao.26.004285}, abstractNote={The effect of a uniform bistable optical transmission defect in the encoding mask on the multiplex efficiency is investigated for solid-state Hadamard transform spectrometry with thermal detection. It is demonstrated that encoding masks which possess nonideal optical transmission properties, i.e., bistable transmission defects, need not impare the multiplex capability provided a sufficient number of resolution elements are multiplexed. Application to the SNR of a general algorithm for the calculation of the average mean square error in the estimate of the spectrum shows that reasonable SNR improvements can be expected when compared to conventional dispersive instruments.}, journal={Applied optics}, year={1987}, month={Oct} }
 @article{tilotta_hammaker_fateley_1987, title={The feasibility of near-infrared electrooptic Hadamard transform Raman spectrometry}, volume={43}, url={http://dx.doi.org/10.1016/s0584-8539(87)80036-3}, DOI={10.1016/s0584-8539(87)80036-3}, abstractNote={Abstract The feasibility of observing Raman spectra in the near i.r. spectral region using a Hadamard transform spectrometer is discussed. The encoding mask for the Hadamard transform spectrometer may be fabricated from a liquid crystal spatial light modulator array (LC-SLM array). The encoding mask may also function as a variable band-pass knife-edge rejection filter for removal of the Rayleigh line to provide selective multiplexing. Hadamard transform Raman spectrometry should compare favourably with Fourier transform Raman spectrometry.}, number={12}, journal={Spectrochimica Acta Part A: Molecular Spectroscopy}, publisher={Elsevier BV}, author={Tilotta, D.C. and Hammaker, R.M. and Fateley, W.G.}, year={1987}, month={Jan}, pages={1493–1495} }
 @article{godziela_tilotta_goff_1986, title={Synthesis and magnetic resonance spectroscopy of novel phenolato-bridged manganese(III) and iron(III)-manganese(III) porphyrin complexes}, volume={25}, url={http://dx.doi.org/10.1021/ic00233a009}, DOI={10.1021/ic00233a009}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and magnetic resonance spectroscopy of novel phenolato-bridged manganese(III) and iron(III)-manganese(III) porphyrin complexesGregory M. Godziela, David Tilotta, and Harold M. GoffCite this: Inorg. Chem. 1986, 25, 13, 2142–2146Publication Date (Print):June 1, 1986Publication History Published online1 May 2002Published inissue 1 June 1986https://doi.org/10.1021/ic00233a009Request reuse permissionsArticle Views203Altmetric-Citations25LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (576 KB) Get e-Alertsclose Get e-Alerts}, number={13}, journal={Inorganic Chemistry}, publisher={American Chemical Society (ACS)}, author={Godziela, Gregory M. and Tilotta, David and Goff, Harold M.}, year={1986}, month={Jun}, pages={2142–2146} }