High‐Performance Liquid Chromatography Methods in Pesticide Residue Analysis

Abstract

AbstractThe important role of high‐performance liquid chromatography (HPLC) in pesticide residue analysis (PRA) is presented. Based on the experience and view of the author, a number of reliable and robust liquid chromatography (LC) approaches and methods have been selected to highlight the favorable features of this technique in this field of analysis.Reversed‐phase liquid chromatography (RPLC) with ultraviolet (UV) detection mode is most widely adopted, owing to its ability to perform efficient separation of very polar to apolar pesticides and the universal character of the detection mode. Therefore, a large part will deal with reversed‐phase liquid chromatography/ultraviolet (RPLC/UV) applications showing its excellent separation performance and detectability of compounds not directly amenable to gas chromatography (GC).Another important feature of RPLC is the possibility of including sample pretreatment steps such as sample concentration and/or cleanup in the analytical procedure. The very good compatibility with aqueous samples or extracts easily permits RPLC on‐line sample loading (trace enrichment) by means of column switching, allowing fully automated procedures. It will be shown that, depending on whether the first column is a low‐ or a high‐resolution column, two different modes of column switching, solid‐phase extraction (SPE) to LC and LC to LC, are adopted in the determination of pesticides. The type of columns and materials, the advantages and the application range of both column‐switching modes is discussed in detail. Attention will be paid to method development including both the straightforward trial‐and‐error approach and more systematic method development procedures.The more selective/sensitive detection modes, fluorescence detection (FD) and mass spectrometry (MS) as applied in pesticides residue analysis will be discussed with emphasis on the increasing importance of MS for identification and quantification of polar pesticides in various types of samples.Finally, the use of LC methods involving normal‐phase liquid chromatography (NPLC), low‐resolution RPLC and gel permeation chromatography (GPC), will demonstrate the powerful sample pretreatment feature of LC prior to gas chromatographic analysis.