PNNL

Abstract

Extensive challenges faced by analytical chemists in studying real world complex samples such as biological body fluids, tissue samples, environmental and geological samples have lead to the development of advanced analytical approaches. The vast array of contemporary technologies can be categorized into two major areas: sample separation and mass spectrometry analysis. Current state-of-the-art sample separation methods include gas chromatography, high performance liquid chromatography, ultra high pressure liquid chromatography, solid phase extraction, capillary electrophoresis, and gas phase separation techniques such as ion mobility spectrometry. The recent trend in sample separation is to combine (or hyphenate) multiple techniques that employ different separation mechanisms to maximize separation efficiency. The most widely used combinations include two-dimensional gas chromatography, strong cation exchange or weak cation exchange chromatography followed by reversed-phase liquid chromatography, two-dimensional reversed-phase liquid chromatography, liquid chromatography followed by ion mobility spectrometry and two-dimensional electrophoresis techniques. The introduction of atmospheric pressure ionization techniques such as electrospray ionization and matrix assisted laser desorption ionization and variations of the two have drastically increased the impact of mass spectrometry on bioanalytical applications. Mass spectrometry itself has tremendously improved over the years in terms of sensitivity, detection limits, dynamic range and sequencing capabilities. Currently, mass spectrometers can attain zeptomolole detection limits with five orders of magnitude dynamic range. In this chapter, we summarize recent developments in hyphenated techniques and their applications to complex sample analysis.