Page 415 - Multidimensional Chromatography

Multidimensional Chromatography
Edited by Luigi Mondello, Alastair C. Lewis and Keith D. Bartle
Copyright © 2002 John Wiley & Sons Ltd
ISBNs: 0-471-98869-3 (Hardback); 0-470-84577-5 (Electronic)

15 Multidimensional Chromatography:

Forensic and Toxicological
Applications

NICHOLAS H. SNOW
Seton Hall University, South Orange, NJ, USA

15.1 INTRODUCTION
In forensic science and toxicology, chemical analysis involves the detection and iden-
tification of compounds that are indicators of disease, poisons, and many types of ille-
gal activities. Often, the analytes are found in difficult matrices such as tissues, urine,
blood, serum, hair, arson debris, and shards of a variety of materials. Since there may
also be many possible analytes for a given sample, extraction and chromatographic
techniques are widely employed in forensic and toxicological analysis as a means for
separating the analytes of interest from the complex matrix, and from each other, prior
to identification. Often, identification by an orthogonal technique such as mass spec-
trometry is required. In classical chromatographic analysis, the complexity of the
samples and matrices, combined with the need for positive identification and quanti-
tative detection of the analytes, generally means that sample preparation methods
must be extensive and laborious. Several authors have recently reviewed classical
methods for forensic and toxicological analysis by using chromatography (1–3).
In order to reduce or eliminate off-line sample preparation, multidimensional chro-
matographic techniques have been employed in these difficult analyses. LC–GC has
been employed in numerous applications that involve the analysis of poisonous com-
pounds or metabolites from biological matrices such as fats and tissues, while
GC–GC has been employed for complex samples, such as arson propellants and for
samples in which special selectivity, such as chiral recognition, is required. Other
techniques include on-line sample preparation methods, such as supercritical fluid
extraction (SFE)–GC and LC–GC–GC. In many of these applications, the chro-
matographic method is coupled to mass spectrometry or another spectrometric detec-
tor for final confirmation of the analyte identity, as required by many courts of law.
In this present chapter, the applications of multidimensional chromatography to
forensic and toxicological analysis are described in detail, being organized by tech-
nique. While multidimensional chromatography has not been as widely applied in