Capillary electrophoresis for forensic drug analysis: A review

doi:10.1016/j.talanta.2005.03.038

Talanta

Volume 67, Issue 2, 15 August 2005, Pages 269-279

https://doi.org/10.1016/j.talanta.2005.03.038 Get rights and content

Abstract

This paper reviews recent applications of capillary electrophoresis to forensic drug analysis and covers the literature since 2001. A brief overview of capillary electrophoresis is followed by a discussion of analytical applications which have been categorized into two sections: (i) drug seizures and non-biological samples, and (ii) forensic toxicology and biological samples.

Introduction

The characterization and quantification of chemical substances in a wide variety of matrices is a challenge faced by forensic scientists. Many forensic samples are complex mixtures, for example biological extracts or debris associated with the scene of an explosion, and analysis generally requires separation prior to identification of chemical species. This has traditionally been carried out using gas chromatography (GC) and high-performance liquid chromatography (HPLC) [1]. Capillary electrophoresis has been investigated as an alternative separation technique for forensic analysis. It has the potential to provide far more rapid separations than are generally achievable with HPLC, and can provide a separation where the analyte in question behaves poorly under GC analysis. This might be due to thermal instability, or at least high-temperature reactivity, as is the case with the drugs, LSD and psilocin (the active ingredient in “magic mushrooms”), the benzodiazepines, and the explosives PETN, RDX and HMX, during GC analysis [1], [2].

The term ‘capillary electrophoresis’ describes a family of related techniques in which separations are carried out in narrow bore capillaries under the influence of an electric field [3]. The separations obtained by capillary electrophoresis are highly efficient, rapid, and may be applied to both charged and neutral species. An on-line search of the Scifinder Scholar database revealed in excess of 30,000 references to capillary electrophoresis to date with applications in a wide range of areas, including pharmaceuticals, food and beverages, environmental and clinical analysis.

The potential of this technique for forensic analysis was first demonstrated in 1991 by Weinberger and Lurie, who applied it to the analysis of a wide range of illicit drugs in synthetic mixtures [4]. Since the first paper, the application of capillary electrophoresis to forensic analysis, as well as comprehensive textbooks and book chapters [14], [15], has been the subject of a number of reviews [5], [6], [7], [8], [9], [10], [11], [12], [13]. The exceptional power of separation and resolution, rapid analysis time, low mass detection limits, economy of reagents, and minimum sample requirements make capillary electrophoresis an attractive methodology for forensic laboratories [9], [16]. In this paper, we review the use of capillary electrophoresis for the determination of drugs in forensic samples since 2001.

Section snippets

Capillary electrophoresis

Electrophoresis can been defined as the differential migration of charged species (ions) in an electric field, and was first described as a separation technique by Tiselius in 1937 [17]. His work, involving the separation of proteins, placed between buffer solutions in a tube across which an electric field was applied, earned him the Nobel Prize for Chemistry in 1948 [18]. His approach to electrophoresis in free solution was limited by incomplete separation due to the effects of thermal

Applications

The application of capillary electrophoresis to the forensic analysis of drugs can be divided into two main areas: the analysis of drug seizures and toxicology.

Conclusions

It is clear from the body of work reviewed above that capillary electrophoresis offers significant operational advantages in terms of resolving power and analysis time. It should also be noted that as the basis for separation is fundamentally different to that in GC and HPLC, it is useful in situations where an orthogonal approach to analysis of forensic samples is required [86].

A major future direction for capillary electrophoresis for forensic analysis is miniaturisation. Capillary

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Capillary electrophoresis for forensic drug analysis: A review

Abstract

Introduction

Section snippets

Capillary electrophoresis

Applications

Conclusions

Forensic Sci. Int.

Sci. Justice

Clin. Chim. Acta

J. Chromatogr. A

Chromatogr. Rev.

Forensic Sci. Int.

J. Chromatogr. A

J. Chromatogr. A

Anal. Chim. Acta

Forensic Sci. Int.

J. Chromatogr. A

J. Chromatogr. A

Forensic Sci. Int.

J. Chromatogr. A

J. Chromatogr. A

J. Chromatogr. A

J. Chromatogr. A

J. Chromatogr.

Forensic Sci. Int.

J. Pharm. Biomed. Anal.

J. Pharm. Biomed. Anal.

J. Chromatogr. B

J. Chromatogr. A

Electrophoresis

Forensic Sci. Int.

J. Chromatogr. A

J. Chromatogr. A

J. Chromatogr. A

J. Chromatogr. B

Anal. Chim. Acta

Drugs of Abuse

Anal. Chem.

Electrophoresis

Fresenius J. Anal. Chem.

J. Liq. Chrom. Rel. Technol.

Ther. Drug Monit.

Am. Lab.

Chimia

Clinical and Forensic Applications of Capillary Electrophoresis

Trans. Faraday Soc.