Examination of Firearms Review: 2007 to 2010 - Interpol

0.3 to 2.0 V, to produce an optimal set of fragment-rich MS/MS spectra for
application of GUS in postmortem blood, urine, and hair specimens [234].
Identification of metabolites in addition to parent drugs are also helpful in the
GUS, and five cases were used to illustrate the utility of screening of xenobiotic
metabolites in routine analysis of forensic samples by employing a previously
published LC-MS/MS GUS procedure [236].
An UPLC-TOFMS method was developed for the routine analysis of urine
samples [238]. By comparison of acquired data to libraries containing more
than 300 common drugs and metabolites, identification was based on a
combination of retention time, exact mass and fragmentation patterns. The use
of TOFMS techniques for screening of drugs in serum [ 239 ], urine
[238,239,240,241] and hair [242,243] have been reported.
Apart from high sensitivity and selectivity, there is also a need of
high-throughput methods to cope with the increasing number of samples
typically submitted to toxicology laboratories. UPLC with sub-2 µm particles
can be operated at higher pressures, resulting in an increase in resolution,
speed and sensitivity comparing with conventional LC [244]. Because the triple
quadrupole MS/MS technique is limited by the cycle time when dealing with a
large amounts of compounds, TOFMS coupled to UPLC is more frequently
adopted in the screening of unknown analytes [240]. For example, a
UPLC-QTOFMS method was developed for fast analysis of 103 doping agents
(such as stimulants, diuretics, narcotics, and anti-estrogens) in urine based on
retention time and mass accuracy, including an automated tool for peak
picking, with a runtime of 9 min for the screening [240] and 7 min for
confirmation with an addition use of SPE [245]. UPLC-TOFMS can be applied
not only in screening of unknown analystes but also for quantitative analysis.
Quantitative analysis using UPLC-TOFMS of 52 common pharmaceuticals and
abused drugs in hair was reported [242]. But the TOF method was found to be
less suitable for quantification of amphetamines, as high background noise
may be observed because of its low molecular mass, leading to a lack of
linearity and poor sensitivity [242]. Identification of drugs metabolites is
sometimes helpful for the identification of their parent compounds, and
software that could predict the metabolites and mass fragmentation pattern of
quetiapine (as analysed by LC-TOFMS) was developed and was found to be
able to assign 13 metabolites in urine samples [246].
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