大体积进样技术在环境分析中的应用

在毛细管气相色谱法(CGC)中,采用大体积进样技术(LVI),即使用能够容纳大体积样品的进样装置以及增加可控时间的溶剂蒸汽放空装置,可以满足环境样品中超痕量组分的分析要求,简化样品浓缩步骤以及实现液相色谱(LC)与CGC的在线联用。针对分析物的性质、毛细管柱的规格和分析的目的已发展了多种LVI。本文总结了几种常见的LVI,包括柱头进样(OCI)和程序升温进样(PTV),以及近年来发展的一些新技术,如在柱同时溶剂浓缩进样、样品直接引入进样/复杂基质进样和同时溶剂冷凝无分流进样,阐述了各种进样技术的基本原理及其与样品提取、LC纯化在线联用的方法在环境分析应用中的一些最新研究进展。

Applications of large-volume injection for environmental analysis

Large-volume injection (LVI) in capillary gas chromatography (CGC) was developed for determining the trace components in environmental samples and for reducing (or even eliminating) the need for cleanup step, also for on-line connection of liquid chromatography (LC) with CGC. The key features of the LVI include sample retained by a large capacity volume liner or a retention gap, and solvent vapor eliminated by solvent vapor exit. There are many kinds of LVI techniques for different analyses, capillary columns and purposes. This review summarizes the recent developments of LVI for environmental analysis, include on column injection (OCI), programmed temperature vaporizer (PTV), AT-column, direct sample introduction/difficult matrix injection, concurrent solvent recondensation large volume splitless injection, and also through oven transfer adsorption desorption interface for on-line connection of LC with CGC.