This review covers the literature on pesticide analysis abstracted and/or published in the period between December 1, 1990 and December 1, 1992. The major sources of information were the primary abstracting journals Chemical Abstracts and Analytical Abstracts. Journals that were searched directly include Journal of the AO AC International, Journal of Agricultural and Food Chemistry, Bulletin of Environmental Contamination and Toxicology, Analytical Chemistry, Analyst, Chromatographia, and Journal of Chromatography (including its bibliography issues). The review is devoted mainly to methods for the determination of residues of pesticides in a wide variety of sample matrices. Areas that are included are listed in the Review Contents. Some coverage is given to the analysis of related industrial chemicals, such as PCBs dioxins, and furans, but pesticide formulation analysis is not reviewed. The attempt was made to choose only the most important publications describing significant advances in methodology, instrumentation, and applications that would be readily available to readers of this journal. Abstract citations are given for references from the more obscure journals and those not published in English. Abbreviations used throughout this review are listed in Table I. Pesticide abbreviations, common names, and trade names are used according to the Pesticide Dictionary of the Farm Chemicals Handbook '92, Meister Publishing Co., Willoughby, OH.Multiresidue methods are used by federal (FDA, USDA, EPA) and state regulatory and monitoring laboratories to analyze a range of pesticide classes in a variety of sample matrices. Multiresidue and single residue methods generally consis tof the following basic steps: extraction of the analyte(s) from the sample matrix; cleanup to remove interfering coextractants; conversion of the analyte to a readily analyzed derivative (if needed); separation of the analytes from each otheT and any remaining interferences, usually by GC or HPLC; detection; quantification by comparison of the detector response of the sample to that of standards; and confirmation of results using an ancillary method, such as MS. Among the more widely used MRMs and SMRMs (which are suitable for pesticides of only a single class) are those of Mills; Mills, Onley, and Gaither; Storherr; Luke; and Krause (1). The Luke method, which involves an aqueous acetone Joseph Sherma received a B.S In chemistry from Upsala College, East Orange. NJ, In 1958 and a Ph.D. in analytical chemistry from Rutgers University in 1958. His thesis research in ion exchange chromatography was under the direction of the late Wm. Rieman III. Dr. Sherma joined the faculty of Lafayette College in Sept 1958 and is presently John D.& Frances H. Larkin Professor and Head of the Department of Chemistry and is in charge of three courses in analytical chemistry. Dr. Sherma independently and with others has written or edited over 370 papers, chapters, books, and reviews covering chromatographic andanalytical methods. His current research Interests are ...
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Illustrated with Chloroplast Pigments flflany of the modifications and applications of chromatography are easily demonstrated with the mixture of green and yellow chloroplast pigments extracted from photosynthetic organisms. These pigments, the chlorophylls and carotenoids, are notable for their deep-green and yellow eolors; hence, they are readily observed as they are separated in the chromato-
SUMMARYClimate change is causing winters to become milder (less cold and shorter). Recent studies of overwintering ectotherms have suggested that warmer winters increase metabolism and decrease winter survival and subsequent fecundity. Energetic constraints (insufficient energy stores) have been hypothesized as the cause of winter mortality but have not been tested explicitly. Thus, alternative sources of mortality, such as winter dehydration, cannot be ruled out. By employing an experimental design that compared the energetics and water content of lizards that died naturally during laboratory winter with those that survived up to the same point but were then sacrificed, we attempt to distinguish among multiple possible causes of mortality. We test the hypothesis that mortality is caused by insufficient energy stores in the liver, abdominal fat bodies, tail or carcass or through excessive water loss. We found that lizards that died naturally had marginally greater mass loss, lower water content, and less liver glycogen remaining than living animals sampled at the same time. Periodically moistening air during winter reduced water loss, but this did not affect survival, calling into question dehydration as a cause of death. Rather, our results implicate energy limitations in the form of liver glycogen, but not lipids, as the primary cause of mortality in overwintering lizards. When viewed through a lens of changing climates, our results suggest that if milder winters increase the metabolic rate of overwintering ectotherms, individuals may experience greater energetic demands. Increased energy use during winter may subsequently limit individual survival and possibly even impact population persistence.
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