Endogenous GHB in Segmented Hair Part II: Intra-individual Variation for Exogenous Discrimination.

The endogenous presence of gamma-hydroxybutyric acid (GHB) complicates the interpretation of results in cases where an exogenous dosing is suspected. Due to GHB's rapid metabolism and clearance following exogenous doses, hair has become a preferential matrix for confirmation of GHB exposure in drug-facilitated crimes. However, unlike blood and urine where an agreed-upon cut-off concentration for differentiation between endogenous and exogenous GHB has been made, there has been no consensus on a cut-off concentration for hair.

Endogenous GHB in Segmented Hair Part I: Inter-individual Variation for Group Comparisons.

While earlier studies have attempted to resolve the challenges encountered when interpreting gamma-hydroxybutyric acid (GHB) concentrations in hair (primarily due to its endogenous presence), few have had large sample sizes. The first objective of this study was to evaluate the inter-individual variation of endogenous GHB concentrations. The second objective, to be detailed in another report, was to assess intra-individual variation and the impact on exogenous GHB discrimination.

Evaluating Endogenous GHB Variation in Hair with a Synthetic Hair Matrix.

The variation in drug concentrations in human head hair from 22 donors was measured using a synthetic hair matrix (SMx™ hair). This matrix is being reported for the first time as a calibrator for an endogenous substance. In comparison to authentic hair or melanin, the synthetic hair provided a reliable batch-to-batch source of liquid matrix similar in composition to authentic hair, but without detectable concentrations of endogenous gamma-hydroxybutyric acid (GHB).

An improved method for the analysis of GHB in human hair by liquid chromatography tandem mass spectrometry.

The abuse of gamma-hydroxybutyric acid (GHB) and its suspicion in cases of suspected drug-facilitated sexual assault is of keen interest to forensic toxicology laboratories. This paper reports an extraction, separation and detection procedure for GHB in hair utilizing a combination of liquid-liquid extraction and solid-phase extraction using ethyl acetate and Oasis Max(®) cartridge, respectively, after the hair sample was digested. Analysis was by LC-MS-MS using a gradient separation on an Acclaim(®) Trinity(TM) P1 column performing three multiple-reaction monitoring (MRM) transitions each for GHB and its internal standard.

Analysis of extensively washed hair from cocaine users and drug chemists to establish new reporting criteria.

Samples from a self-proclaimed cocaine (COC) user, from 19 drug users (postmortem) and from 27 drug chemists were extensively washed and analyzed for COC, benzoylecgonine, norcocaine (NC), cocaethylene (CE) and aryl hydroxycocaines by liquid chromatography-tandem mass spectrometry. Published wash criteria and cutoffs were applied to the results. Additionally, the data were used to formulate new reporting criteria and interpretation guidelines for forensic casework.

An HPLC-HR-MS-MS method for identification of anticoagulant rodenticides in blood.

This paper presents a fully validated method for the qualitative identification of bromadiolone, brodifacoum, coumachlor, coumatetralyl, difenacoum and warfarin in whole blood specimens. Samples are protein precipitated with acetonitrile, processed via solid-phase extraction and analyzed by high-performance liquid chromatography with high resolution tandem mass spectrometric detection. Limits of detection were 10 ng/mL or better for all analytes.

The role of variations in growth rate and sample collection on interpreting results of segmental analyses of hair.

Segmental analysis of hair for drugs, metabolites, and poisons has been widely reported in the scientific literature over the past two decades. Two fundamental assumptions in interpreting results of such analyses are (1) an average linear growth rate of head hair of 1cm/month and (2) that sample collections occur with the hair being cut directly next to the scalp. The purpose of this study was to evaluate the variability associated with growth rate of human head hair, as well as the ability to uniformly collect hair next to the scalp.

A fast method for screening and/or quantitation of tetrahydrocannabinol and metabolites in urine by automated SPE/LC/MS/MS.

Marijuana is one of the most commonly used illicit substances. The high usage of this substance results in it being commonly encountered in clinical samples throughout the USA and Europe. Due to its wide availability and use, marijuana is also commonly encountered in forensic toxicology laboratories.

A semi-automated solid-phase extraction liquid chromatography/tandem mass spectrometry method for the analysis of tetrahydrocannabinol and metabolites in whole blood.

Marijuana is one of the most commonly abused illicit substances in the USA, making cannabinoids important to detect in clinical and forensic toxicology laboratories. Historically, cannabinoids in biological fluids have been derivatized and analyzed by gas chromatography/mass spectrometry (GC/MS). There has been a gradual shift in many laboratories towards liquid chromatography/mass spectrometry (LC/MS) for this analysis due to its improved sensitivity and reduced sample preparation compared with GC/MS procedures.

Rapid analysis of cocaine and metabolites in urine using a completely automated solid-phase extraction-high-performance liquid chromatography-tandem mass spectrometry method.

A rapid, simple, and completely automated method for the analysis of cocaine and its metabolites in urine has been developed. The method utilizes online solid-phase extraction (SPE) with liquid chromatographic separation and tandem mass spectrometric detection (MS-MS). An efficient online SPE procedure was developed using Hyspheretrade mark MM anion sorbent.

An automated SPE/LC/MS/MS method for the analysis of cocaine and metabolites in whole blood.

As laboratories are called upon to develop novel, fast, and sensitive methods, here we present a completely automated method for the analysis of cocaine and its metabolites (benzoylecgonine, ecgonine methyl ester, ecgonine and cocaethylene) from whole blood. This method utilizes an online solid-phase extraction (SPE) with high performance liquid chromatographic separation and tandem mass spectrometric detection. Pretreatment of samples involve only protein precipitation and ultracentrifugation.

Further evidence of in vitro production of gamma-hydroxybutyrate (GHB) in urine samples.

This study was designed to supplement previous studies that documented in vitro production of gamma-hydroxybutyrate (GHB) in urine samples. Urine samples were provided by subjects who reported that they had never used GHB (n=31). The specimens were stored under standard conditions of refrigeration (5 degrees C) without any preservatives added.

A comprehensive study on the variations in urinary concentrations of endogenous gamma-hydroxybutyrate (GHB).

This study was designed to supplement previous attempts to establish an accurate range of normal endogenous gamma-hydroxybutyrate (GHB) concentrations in random antemortem urine samples. Furthermore, its purpose was to ascertain the effect of gender, race, age, medications, and select medical conditions on endogenous concentrations of GHB in urine and the proposed endogenous urinary GHB cutoff of 10 microg/mL. Urine samples (n = 207) were provided by subjects who reported that they had never used GHB.

Qualitative identification of doxacurium and its breakdown products in postmortem fluids by liquid chromatography-tandem mass spectrometry.

During a death investigation at the Office of the Cuyahoga County Coroner in Cleveland, OH, doxacurium became a drug of interest. The Coroner's Office enlisted the aid of the Federal Bureau of Investigation Laboratory for the doxacurium analysis. Following the request, a method for the extraction and qualitative analysis of the drug in biological fluids was developed.

The identification of mivacurium and metabolites in biological samples.

Mivacurium is a muscle relaxant that is used in hospitals and has been implicated in a number of homicides. A validated, sensitive method for the analysis of mivacurium and metabolites from biological specimens is presented here. Sample cleanup involves the precipitation of proteins with acetonitrile followed by analyte isolation using a commercially available solid-phase extraction column.

Capillary electrophoresis screening of poisonous anions extracted from biological samples.

A method was developed for screening human biological samples for poisonous anions using capillary electrophoresis (CE) employing indirect UV detection. The run buffer consisted of 2.25 mM pyromellitic acid, 1.