Environmental and Reaction Monitoring

Pesticides and polynuclear aromatics (PNAs) are the most commonly analyzed environmental contaminants. Analysis of PCBs, dioxans, and nitroor-ganics (explosives) is of growing importance. The major obstacles to adoption of environmental HPLC application are 1) awareness of the need, (i.e., environmental and drinking water contamination) and 2) the slow rate of development and acceptance of new AOAC and EPA-mandated HPLC and LC/MS methods. 

Pesticides can be analyzed on a C18 column, the chlorinated hydrocarbon type (chlordane) at 80% An/water UV, 220 nm, the carbamate type (sevin) at 40% An/water UV, 254 nm, and the organic phospahate (malathion) at 50% An/water with UV, 192 nm or with a CAD. The organic phosphate types are hard to detect at low concentration and various phosphate analysis techniques have been evaluated. LC/MS, where available, is the technique of choice for analyzing all of these pesticides, but especially the organic phosphates, in a general gradient HPLC scheme. 

PNAs are analyzed at UV, 254 nm, on C18 column in 80% An/water. PCBs can be analyzed with the same conditions. Dioxans require detection at UV, 220 nm, and 50% An/water on a C18 column. 

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