Biomedical Engineering Reference
In-Depth Information
Since errors in analytical forensic toxicology may lead to legal consequences for
both the offender and the injured, obtaining meaningful and reliable analytical data
is mandatory.
Liquid chromatography-mass spectrometry or tandem mass spectrometry (LC-
MS or LC-MS/MS) has helped this field closing the gap with respect to hydrophilic,
thermolabile, and nonvolatile analytes, which were not sufficiently covered by the
established gold standard technique gas chromatography-mass spectrometry (GC-
MS) [ 52 ]. Jenkins et al. compared with each other LC-MS, LC-UV, and GC-MS
determination of the specific case of MDMA showing how the coupling LC-MS
technique is very versatile, sensitive, and selective for the analysis of drugs of abuse
and pretreatment is relatively simple [ 53 ]. LC-MS and LC-MS/MS are thus largely
replacing GC-MS and GC-MS/MS in the analysis of drugs of abuse, because it does
not require derivatization and is capable of simultaneous determination of both con-
jugated drugs of abuse and free forms in a single analysis without the intermediate
step of hydrolysis pretreatment of the sample: these are important advantages in
terms of analysis time and performance [ 54 ] .
Its largest field of application, which will focus on this chapter, is the multire-
sidual analysis in biological samples. In so-called confirmatory analyses, LC-MS,
or better LC-MS/MS, provides an unequivocal identification, due to the high selec-
tivity of the MS detector. The results of Systematic Toxicological Screening Analysis
(STA) or General Unknown Screening (GUS), other applications of LC-MS, needs
of subsequent confirmatory analysis to be used in a court [ 52, 55 ] .
7.1
Development of an Analytical Method: Guidelines
Specific guidelines or procedures have been adopted in order to assist the chemist
and to direct him towards the practical applications, for which a new analytical
method is being created, including measures of verification and external
assessment.
In 1996 the American Board of Forensic Toxicology launched the Forensic
Toxicology Accreditation Program based on the guidelines of the Society of Forensic
Toxicologists in American Academy of Forensic Sciences (SOFT/AAFS): the final
document was adopted and the latest version was published in 2006 [ 56 ] . In Europe
there is a document relating to the performance of analytical methods and interpre-
tation of results aimed to identification of drug residues in foodstuffs, which is
sometimes used also for forensic purposes: the decision 2002/657/EC [ 57 ] . The
German guidelines of the Society of Toxicological and Forensic Chemistry (GTFCh)
are exquisitely forensic. In 2006 a document entitled “Drugs of Abuse Testing
Guidelines” was published by AGSA (Swiss Working Group for Drugs of Abuse
Testing Guidelines) and supported by the major public institutions in Switzerland.
However, there are also those issued by the Food and Drugs Administration (FDA)
relating bioanalytical method [ 58 ], sometimes supplemented with EMEA's homo-
logue document [ 59 ] and SOFT-AAFS or 2002/657/EC [ 57 ] . SOFT-AAFS guidelines
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