Signal enhancement of glucuronide conjugates in LC-MS/MS by derivatization with the phosphonium propylamine cation tris(trimethoxyphenyl) phosphonium propylamine, for forensic purposes.

Although chemical derivatization for signal enhancement in drug testing is most often associated with gas chromatography, it also has the potential to improve the detection of analytes poorly ionized by atmospheric pressure ionization techniques, such as electrospray ionization used in liquid chromatography-mass spectrometry. A number of acidic compounds, namely drug glucuronides (e.g.

A comparison of the performance of quality controls prepared from spiked, fortified and authentic hair for ethyl glucuronide analysis.

Ethyl glucuronide (EtG) quantification in hair was assessed using quality controls prepared by three methods: (a) spiking hair samples with known concentrations of EtG, (b) fortifying hair by incubation of blank hair with EtG for several days or (c) use of authentic hair samples positive for EtG. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed on a Shimadzu model 8030 instrument and validated for the quantification of EtG. For two concentration levels, approximately 50 and 500 pg/mg QCs, EtG concentrations were measured in duplicate (N=2) on 8 days (N=16) and intra-assay precision (repeatability) and inter-assay precision determined using one-way analysis of variance.

Detection of ketamine and its metabolites in human hair using an integrated nanoflow liquid chromatography column and electrospray emitter fritted with a single porous 10 μm bead.

Targeting metabolites incorporated into hair following drug administration is useful for evidential purposes as this approach can aid in differentiating between administration and passive exposure. Greater analytical sensitivity is required than for targeting the parent drug alone. A 20 μm i.

An evaluation of the DRI-ETG EIA method for the determination of ethyl glucuronide concentrations in clinical and post-mortem urine.

A commercial enzyme immunoassay for the qualitative and semi-quantitative measurement of ethyl glucuronide (EtG) in urine was evaluated. Post-mortem (n=800), and clinical urine (n=200) samples were assayed using a Hitachi 902 analyzer. The determined concentrations were compared with those obtained using a previously published liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of EtG and ethyl sulfate.

Use of human microsomes and deuterated substrates: an alternative approach for the identification of novel metabolites of ketamine by mass spectrometry.

In vitro biosynthesis using pooled human liver microsomes was applied to help identify in vivo metabolites of ketamine by liquid chromatography (LC)-tandem mass spectrometry. Microsomal synthesis produced dehydronorketamine, seven structural isomers of hydroxynorketamine, and at least five structural isomers of hydroxyketamine. To aid identification, stable isotopes of the metabolites were also produced from tetra-deuterated isotopes of ketamine or norketamine as substrates.

Detection of ketamine and its metabolites in urine by ultra high pressure liquid chromatography-tandem mass spectrometry.

Current analytical methods used for screening drugs and their metabolites in biological samples from victims of drug-facilitated sexual assault (DFSA) or other vulnerable groups can lack sufficient sensitivity. The application of liquid chromatography, employing small particle sizes, with tandem mass spectrometry (MS/MS) is likely to offer the sensitivity required for detecting candidate drugs and/or their metabolites in urine, as demonstrated here for ketamine. Ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) was performed following extraction of urine (4 mL) using mixed-mode (cation and C8) solid-phase cartridges.