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Extraction and cleanup methods used for the analysis of organophosphate pesticides are similar to those used for chlorinated hydrocarbons but differ in some important details. Many organophosphates are lost during extraction of acetonitrile solutions containing organophosphates with petroleum ether; dichloromethane is substituted. Also, cleanup by column chromatography on mixed adsorbents containing charcoal results in better recoveries than can be obtained on Florisil alone. The detectors used for measurement of organophosphates by GLC are almost unique for this group of compounds. TLC is very useful for confirming the identities of the compounds, and several promising optical methods are available for their measurement. Methods for the analysis of metabolites of this group are basically similar, since all organophosphates undergo dealkylation reactions and cleavage of the acid anhydride bond. However, measurement of the polar group which is removed during phosphorylation or other reactions involving cleavage of the acid anhydride bond is a problem unique for each compound.

The utility of a variety of chromatographic procedures (GLC, TLC, and GLC/MS) has been described for the determination of a variety of methylene dioxyphenyl insecticide synergists. Particular focus was placed on chromatographic aspects of the principal synergist, piperonyl butoxide, in relation to its trace impurities, determination in formulations, metabolism, residues, and stability.

Of the more conventional pesticidal chemicals, the carbamate insecticides pose some unique problems relative to residue analysis. Most of these compounds are unstable under conditions normally used for GLC analysis and require special attention if this technique is to apply to the carbamates. Moreover, the carbamates are commonly metabolized to products which are toxicologically significant and which must be included in any analytical considerations. These and other problems inherent in carbamate residue methodology are discussed in this report along with technique currently utilized or having potential as sound procedures for the analyses of carbamate insecticides.

Environmental monitoring is now recognized as essential in areas of pesticide use in order to assess the impact of these pesticides on the environment. During the last two decades, advances in instrumentation in terms of detection limits and specificity, along with the growing expertise of residue chemists, have made reports of pesticide residue levels in the parts per billion range commonplace. Using this technical ability and carefully assessing the significance of the data obtained, pesticides can be used in a more efficacious manner with less possible damage to the environment.

This article reviews the methodology required for triglyceride analysis by gas liquid chromatography. Compositions of the animal and vegetable triglyceride mixtures to which this technique has been applied are summarized.