@article{boes_roberts_vinueza_2018, title={Rapid Quadrupole-Time-of-Flight Mass Spectrometry Method Quantifies Oxygen-Rich Lignin Compound in Complex Mixtures}, volume={29}, ISSN={["1879-1123"]}, DOI={10.1007/s13361-017-1847-0}, abstractNote={Complex mixture analysis is a costly and time-consuming task facing researchers with foci as varied as food science and fuel analysis. When faced with the task of quantifying oxygen-rich bio-oil molecules in a complex diesel mixture, we asked whether complex mixtures could be qualitatively and quantitatively analyzed on a single mass spectrometer with mid-range resolving power without the use of lengthy separations. To answer this question, we developed and evaluated a quantitation method that eliminated chromatography steps and expanded the use of quadrupole-time-of-flight mass spectrometry from primarily qualitative to quantitative as well. To account for mixture complexity, the method employed an ionization dopant, targeted tandem mass spectrometry, and an internal standard. This combination of three techniques achieved reliable quantitation of oxygen-rich eugenol in diesel from 300 to 2500 ng/mL with sufficient linearity (R2 = 0.97 ± 0.01) and excellent accuracy (percent error = 0% ± 5). To understand the limitations of the method, it was compared to quantitation attained on a triple quadrupole mass spectrometer, the gold standard for quantitation. The triple quadrupole quantified eugenol from 50 to 2500 ng/mL with stronger linearity (R2 = 0.996 ± 0.003) than the quadrupole-time-of-flight and comparable accuracy (percent error = 4% ± 5). This demonstrates that a quadrupole-time-of-flight can be used for not only qualitative analysis but also targeted quantitation of oxygen-rich lignin molecules in complex mixtures without extensive sample preparation. The rapid and cost-effective method presented here offers new possibilities for bio-oil research, including: (1) allowing for bio-oil studies that demand repetitive analysis as process parameters are changed and (2) making this research accessible to more laboratories. Graphical Abstract ᅟ.}, number={3}, journal={JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY}, author={Boes, Kelsey S. and Roberts, Michael S. and Vinueza, Nelson R.}, year={2018}, month={Mar}, pages={535–542} }
 @article{boes_narron_chen_park_vinueza_2017, title={Characterization of biofuel refinery byproduct via selective electrospray ionization tandem mass spectrometry}, volume={188}, ISSN={["1873-7153"]}, DOI={10.1016/j.fuel.2016.10.016}, abstractNote={To achieve economic viability, biorefineries need to increase efficiency through characterization of byproducts for the purpose of valorization. One such byproduct is the liquid stream produced after autohydrolysis pretreatment, autohydrolyzate liquor, which contains valuable organic derivatives of hemicellulose and lignin from biomass. To characterize the autohydrolysis liquor, we employed a novel method for such liquor analysis that uses electrospray ionization and ion dopants in combination with tandem mass spectrometry using a quadrupole–time-of-flight mass spectrometer. Electrospray expands current analysis of such liquors through softer ionization. Ion dopants provide for differentiation of the complex mixture components without requiring derivatization or preliminary separation. The dopants—ammonium chloride and sodium hydroxide—primarily target and enhance ionization of hemicellulosic or lignin derivative species, respectively, based on the species’ differing functionalities. Valuable structural information can be gleaned from these enhanced species by ion isolation and collision-activated dissociation (CAD), which reveals the presence of hemicellulosic or lignin derivative functionalities. These ionization techniques coupled with CAD enabled us to not only confirm the presence of low molecular weight ions, such as vanillin, as previously seen with gas chromatography-mass spectrometry but also expand the characterization to high molecular weight species. This expanded knowledge of the composition of autohydrolyzate liquor opens up the potential to develop lucrative co-products from this stream in a commercial biorefinery.}, journal={FUEL}, author={Boes, Kelsey S. and Narron, Robert H. and Chen, Yufei and Park, Sunkyu and Vinueza, Nelson R.}, year={2017}, month={Jan}, pages={190–196} }