Chapter 5 Sample introduction techniques

Abstract

Publisher Summary This chapter presents an overview of the various sample-introduction techniques for both gas chromatography (GC) and liquid chromatography (LC), as applied to the analysis of pesticide residues in fruits and vegetables. The analysis of pesticide residues includes traditional injection techniques—such as split/splitless or on-column injection—as well as recent techniques—such as the programmable temperature vaporizer, large volume injection (LVI), and automated coupling to a sample preparation unit. Solid-phase microextraction (SPME) is also discussed for the analysis of pesticide residues in food. The chapter provides information on the functioning principle of these techniques along with their advantages and limitations. The most appropriate injection procedure to be used for a reliable quantification of pesticides of different physico-chemical properties is discussed. The chapter describes effective injection methods that provide (1) precision of the injection volume, (2) no carry-over effects, and (3) high versatility. It also describes the way by which they can be used for routine analysis of pesticides in food matrices. Automated procedures are highlighted because of the ever-increasing need for routine analysis of pesticides in food with minimum sample handling.