@article{zhou_merrick_khaledi_tomer_2000, title={Detection and sequencing of phosphopeptides affinity bound to immobilized metal ion beads by matrix-assisted laser desorption/ionization mass spectrometry}, volume={11}, ISSN={["1879-1123"]}, DOI={10.1016/S1044-0305(00)00100-8}, abstractNote={Consecutive enzymatic reactions of analytes which are affinity bound to immobilized metal ion beads with subsequent direct analysis of the products by matrix-assisted laser desorption/ionization mass spectrometry have been used for detecting phosphorylation sites. The usefulness of this method was demonstrated by analyzing two commercially available phosphoproteins, beta-casein and alpha-casein, as well as one phosphopeptide from a kinase reaction mixture. Agarose loaded with either Fe3+ or Ga3+ was used to isolate phosphopeptides from the protein digest. Results from using either metal ion were complementary. Less overall suppression effect was achieved when Ga3+-loaded agarose was used to isolate phosphopeptides. The selectivity for monophosphorylated peptides, however, was better with Fe3+-loaded agarose. This technique is easy to use and has the ability to analyze extremely complicated phosphopeptide mixtures. Moreover, it eliminates the need for prior high-performance liquid chromatography separation or radiolabeling, thus greatly simplifying the sample preparation.}, number={4}, journal={JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY}, author={Zhou, W and Merrick, BA and Khaledi, MG and Tomer, KB}, year={2000}, month={Apr}, pages={273–282} }
 @inproceedings{wang_hesterberg_zhou_sayers_robarge_1997, title={Extended x-ray absorption fine structure study of mercury speciation in a flood plain soil}, number={1997}, booktitle={Contaminated soils: 3rd International Conference on the Biogeochemistry of Trace Elements, Paris (France), May 15-19, 1995}, publisher={Paris: INRA Editions}, author={Wang, Z. and Hesterberg, D. and Zhou, W. and Sayers, D. E. and Robarge, W. P.}, year={1997} }
 @article{hesterberg_sayers_zhou_plummer_robarge_1997, title={X-ray absorption spectroscopy of lead and zinc speciation in a contaminated groundwater aquifer}, volume={31}, ISSN={["1520-5851"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0031260138&partnerID=MN8TOARS}, DOI={10.1021/es970077w}, abstractNote={The formation of insoluble metal sulfides in the environment may reduce the mobility and bioavailability of heavy metal contaminants and potentially eliminate the need for ex situ remediation of certain hazardous waste sites. To assist in assessing remediation strategies for the Bypass 601 Superfund site, groundwater aquifer samples were analyzed using synchrotron X-ray absorption spectroscopy (XAS) to determine whether lead and zinc sulfides were dominant mineral phases. Moist aquifer solids contained between 150 and 1800 mg of Pb/kg and between 100 and 250 mg of Zn/kg. Lead sulfide was not dominant in any of the samples analyzed, including one sample collected from a well in a flood plain that contained 70% of zinc bonded to sulfur, probably as ZnS. This portion of the aquifer had apparently been under reducing conditions. In all other samples, first-shell bonding of Pb and Zn was predominantly to oxygen. Data indicated that PbO, PbCO3, PbSO4, and ZnO were not dominant metal species. The XAS analyses sh...}, number={10}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Hesterberg, D and Sayers, DE and Zhou, WQ and Plummer, GM and Robarge, WP}, year={1997}, month={Oct}, pages={2840–2846} }
 @article{hesterberg_sayers_zhou_robarge_plummer_1997, title={XAFS Characterization of Copper in Model Aqueous Systems of Humic Acid and Illite}, volume={7}, ISSN={1155-4339}, url={http://dx.doi.org/10.1051/jp4:1997253}, DOI={10.1051/jp4:1997253}, abstractNote={Adsorption of heavy metals at mineral surfaces and complexation with reactive organic-matter functional groups are important processes regulating the solubility and fate of soil contaminants. To determine the nature of Cu(II) bonding in complex clay-organic systems, XAFS analyses were conducted on aqueous suspensions containing Cu(II) in various forms: (i) complexed with soil humic acid (HA) at various HA:Cu ratios, (ii) bound to illite, or (iii) bound in a mixture of illite and HA. Spectral features for Cu bound to HA did not depend significantly on the HA:Cu ratio, and average first-shell Cu-O bond lengths were consistently shorter than for the Cu-illite systems. In the mixed clay-organic suspension, Cu bonding was more characteristic to that of Cu bound with HA.}, number={C2}, journal={Le Journal de Physique IV}, publisher={EDP Sciences}, author={Hesterberg, D. and Sayers, D. E. and Zhou, W. and Robarge, W. P. and Plummer, G. M.}, year={1997}, month={Apr}, pages={C2–833-C2–834} }
 @article{sayers_hesterberg_zhou_robarge_plummer_1997, title={XAFS characterization of copper contamination in the unsaturated and saturated zones of a soil profile}, volume={7}, ISSN={["1155-4339"]}, DOI={10.1051/jp4:1997252}, abstractNote={The fate of heavy-metal contaminants in the environment, and the design and success of remediation strategies at hazardous waste sites depend on the chemical speciation of the contaminants. The objective of this study was to determine the molecular-scale chemical form (species) of heavy metals in different zones of a contaminated soil having a shallow ground water table. Copper in the unsaturated surface horizon and the water-saturated and partially-saturated subsurface horizons of a disturbed soil from the lower eastern coastal plain of North Carolina was characterized using XAFS spectroscopy. Extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge structure (XANES) data showed that the dominant form of Cu(II) bonding ranged from Cu-S in the deeper soil zones to Cu-O in the shallowest zone. The results suggest that the surface and subsurface horizons will respond differently to remediation treatments.}, number={C2}, journal={JOURNAL DE PHYSIQUE IV}, author={Sayers, DE and Hesterberg, D and Zhou, W and Robarge, WP and Plummer, GM}, year={1997}, month={Apr}, pages={831–832} }