Forensic Applications of HPLC

Forensic science encompasses a number of different fields of science. In this book, we are explaining the theories associated with high performance liquid chromatography, the different forms that it may take, and its use in some forensic applications. In this chapter, we will examine applications of HPLC in drug analysis, toxicology, analysis of explosives, analysis of coloured materials, and environmental science. 

Samples that may contain controlled drug substances can be submitted to the laboratory in a variety of forms. This includes trace samples and bulk samples. Examples of trace samples may include, but are not limited to, swabs from surfaces where drug substances may have been prepared or from paraphernalia that may have been used in the administration of a controlled substance (very small amounts of which may not be visible to the naked eye). Bulk samples may include, but are not limited to, tablets, powders, plant material, resins, and liquids. 

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Multitarget forensic applications of HPLC for other drug classes are also available in the literature. Josefsson et al. [77] applied HPLC-MS-MS to the determination of 19 neuroleptics and their major metabolites in human tissues and body fluids. Optimal separation was achieved using a cyano column within a 9 min gradient run. Detection was curried out in SRM reaching LQDs down to the lower ng/mL level, although more than a 10-fold difference in signal response was observed between analytes. The method was subjected to partial validation only. 

As mentioned previously, the analysis of amphetamines and other basic drugs was one of the first forensic applications of HPLC. Many analyses of basic drugs are still performed by the same method of ion-exchange chromatography on unmodified silica columns with an eluent buffered to about pH 9. Dissolution of the silica in the analytical column is prevented by using a pre-saturation column which is packed with a 40 pm particle size silica. This type of column is situated in the eluent line between the pump and the injection valve and should always be used when performing analyses with aqueous eluents on silica-based columns. By using these columns the lifetime of the analytical column can be extended considerably. 

Bayne, S. Carlin, M. Forensic Applications of HPLC. Taylor Francis Boca Raton, FL, 2010. 

This chapter introduced the application of HPLC and HPCE to forensics, the use of science in the judicial process. We explored how these separation techniques are used in testing for illicit drugs, gunshot residues and explosive constituents, pen inks, modified proteins, and nucleic acids. 

Applications of HPLC Of the bioanalytical separation technologies described in this book, arguably HPLC has the widest range of applications, being adopted for the purpose of clinical, environmental, forensic, industrial, pharmaceutical and research analyses. While there are literally thousands of different applications, a few indicators of how HPLC has been used are as follows (i) Clinical quantification of drugs in body fluids (ii) Environmental identification of chemicals in drinking water (iii) Forensic analysis of textile dyes (iv) Industrial stability of compounds in food products (v) Pharmaceutical quality control and shelf-life of a synthetic drug product (vi) Research separation and isolation of components from natural samples from animals and plants. 

Several HPLC oxidative electrochemical methods have been developed for the analyses of drugs and metabolites in body fluids and the quantitative analysis of morphine was one of the first forensic applications of this detection technique. By applying a potential of +0.6V (versus an Ag/ AgCl reference electrode) the presence of morphine can be confirmed in whole blood and a detection level of 10 ng ml for a 100-pl sample can be achieved routinely. 

F. Tagliaro, Z. Deyl, and I. Miksik, Applications of HPLC/HPCE in forensic, in HPLC in Enzymatic Analysis (E. F. Rossomando, ed), Methods in Biochemical Analysis Vol. 38, John Wiley Sons, New York, 1998, pp. 164-206. 

Many of the applications within forensic science adopt a reverse phase (RP) HPLC mode of separation in relation to analyses. We have chosen to use example applications of HPLC based on this particular mode of chromatography because it is the most frequently used. We have broken each chapter down into theoretical considerations with examples where appropriate, a key point summary, a series of questions where appropriate, and, finally, a list of books and journal articles that we believe will give further, thorough insight into each of the topics covered. We have attempted to keep the book as succinct as possible whilst still providing sufficient information to allow the reader to develop his or her knowledge at an effective pace. 

Chapter 11 looks at some of the applications of HPLC within the field of forensic science in greater detail. We have covered the most common areas, but we acknowledge that both HPLC and forensic science are far-reaching fields of study. 

HPLC has had considerable success in separating compounds as diverse as steroids, carbohydrates, vitamins, dyestuffs, pesticides and polymers. It is used routinely for the assay of pharmaceutical products, the monitoring of drugs and metabolites in body fluids and for other biomedical, biochemical and forensic applications, such as the detection of drugs of abuse. The determination of additives in foodstuffs and beverages including sugars,... 

X. Xu, A.M. van der Craats, E.M. Kok and P.C.A.M. de Bruyn, Trace analysis of peroxide explosives by high performance liquid chromatography — atmospheric pressure chemical ionization — tandem mass spectrometry (HPLC-APCl-MS/MS) for forensic applications ,... 

The first section of the book explores emerging novel aspects of HPLC and related separation methods based on the differential velocity of analytes in a liquid medium under the action of either an electric field (capillary electromigration techniques) or a gravitational field (field-flow fractionation). The section focusing on applications highlights four significant areas in which HPLC is successfully employed chiral pharmaceutical, environmental analysis, food analysis, and forensic science. 

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