Analysis of agrochemical compounds and related impurities by chromatographic-mass spectrometric methods.

Agrochemicals and pesticides are compounds of significant industrial and commercial importance. Over recent years, legislation has increased greatly and with this increased regulation, the necessity for trace impurity analysis of pesticides has grown. Modem chromatographic techniques with both UV and mass spectrometric detection have been used in the study of pesticidal compounds to separate and characterise impurities present at low levels. The use of these techniques is evaluated and suggestions for future work are outlined. The use and analysis of the pesticidal study compounds are reviewed and the instrumental techniques of capillary electrophoresis (CE), mass spectrometry (MS) and high performance liquid chromatography (HPLC) are described. The quaternary ammonium herbicide Paraquat is amongst the most widely used herbicidal products worldwide. The technique of capillary zone electrophoresis (CZE) was evaluated as a means of separating paraquat from a mixture of related impurity compounds. The preconcentration technique of transient capillary isotachophoresis (tCITP) was examined as a means of improving detection limits. Both CZE and tCITP were used successfully in the analysis of technical paraquat. CE-MS was performed with varying levels of success. Flutriafol is a fungicidal compound widely used in the control of cereal diseases. HPLC methodology was developed for use in the separation of flutriafol from a mixture of related impurity compounds. The technique was successfully used in the analysis of a sample of production material with over 25 impurity peaks detected. HPLC-MS was performed and the use of SIM, SRM and CRM were investigated as a means of improving detection limits. HPLC-MS was used in the analysis of a production sample and over twenty peaks were detected in the total ion chromatogram (TIC). The mass spectral information obtained enabled the tentative identification of a number of impurities