Pesticides usage monitoring

Thomas, M.R. (2001) Pesticide usage monitoring in the United Kingdom. Annals of Occupational Hygiene 45(1001), S87-S93. 

Ideally, to support a higher tier assessment that accurately portrays the risks to individuals depending on where they live and who they are, one would have monitoring and pesticide usage data from across the nation for multiple years in such exquisite... 

Climatic fluctuations, long-term usage trends and agronomic practices can dramatically affect the characteristics of the monitoring data obtained from a field study, and this in turn affects the degree to which the study can be utilized to generalize about the environmental impacts of use of the pesticide. Surface water programs should be multi-year studies if one intends to address adequately the variability of pesticide... 

SPE has been applied to phthalate esters (plasticisers in PVC), polar pesticides (agricultural usage) and for other continuous pollution monitoring problems and environmental analyses [272]. For these applications SPE has largely displaced LLE as the preferred technique for the preparation of liquid samples, e.g. EPA method 506 is concerned with the determination of phthalates and adipate esters in drinking water. 

One of the requirements of this approach is that the analytes must be stable at the boiling point of the solvent, since the analytes collect in the flask. The solvent must show high solubility for the analyte and none for the sample matrix. Since this is one of the oldest methods of sample preparation, there are hundreds of published methods for all kinds of analytes in as many matrices. For example, XAD-2 resin (sty-rene-divinylbenzene) that was used to collect air samples to monitor current usage of pesticides in Iowa was Soxhlet-extracted for 24 h with hexane/acetone [22], This is common in environmental sample analysis, and one will see rows and rows of these systems in environmental laboratories. One disadvantage of Soxhlet extraction is the amount of solvent consumed, though modern approaches to solid sample extraction have tried to reduce the amount of solvent used. 

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