Karen S. Scott

The Use of Vitreous Humor as an Alternative to Whole Blood for the Analysis of Benzodiazepines

In postmortem drug analysis, the most commonly used sample matrix is whole blood. However, postmortem changes can denature this matrix, resulting in a loss or degradation of drugs, thus biasing analytical findings. Vitreous humor is thought to be less affected by these changes and should, therefore, have the potential to provide a more reliable estimation of antemortem drug concentrations. To assess the usefulness of vitreous humor for the analysis of benzodiazepine drugs, vitreous humor and whole blood were obtained postmortem in 27 cases. Three benzodiazepine drugs were investigated-temazepam, diazepam, and desmethyldiazepam. For temazepam and diazepam, some correlation was found between the matrices (R2 = 0.789 and 0.724, respectively). However, for desmethyldiazepam, no correlation was observed (R2 = 0.068). Regression analysis on plots of vitreous humor versus blood concentrations produced gradients of less than 1.0 showing that, in general, levels in blood are higher than the corresponding levels in vitreous humor.

The use of hair as a toxicological tool in DFC casework

When drugging related offences are cited, most people think of sexual assault. However, the law covers any crime committed whilst the complainant is under the influence of alcohol or drugs, i.e., the use of a drug to modify a persons behaviour for criminal gain. The case types encountered include robbery, blackmail and of course sexual offences. Hair analysis for drugs is now well established in Forensic Toxicology. Its use as an analytical tool in workplace testing, post-mortem toxicology and criminal cases is expanding both in the U.K. and worldwide, and it is now widely accepted as an alternative or complimentary matrix for these cases. This paper will provide a brief overview of hair testing in cases of Drug Facilitated Crime stressing the importance of timely sample collection. Its usefulness in cases of this type will be highlighted through case examples.

Analysis of ethyl glucuronide in hair samples by liquid chromatography‐electrospray ionization–tandem mass spectrometry (LC‐ESI‐MS/MS)

Many different biomarkers can be used to evaluate ethanol intake. Ethyl glucuronide (EtG) is a direct phase II and minor metabolite of ethanol formed through the UDP‐glucuronosyl transferase‐catalyzed conjugation of ethanol with glucuronic acid. Its investigation is of interest in both clinical and forensic contexts because of the wide window of detection. A sensitive LC‐MS/MS procedure has been developed and fully validated according to the guidelines of forensic toxicology for the analysis of EtG in hair. Sample preparation and chromatographic separation were thoroughly optimized. The analysis was performed in the multiple reaction monitoring mode using the transitions m/z 221 → 203 (for the quantification) and 221 → 85 or 75 (for the qualification) for EtG, and m/z 226 → 208 (for quantification) and 226 → 75 or 85 (for qualification) for EtG‐D5, used as the internal standard. Analyses were carried out using an Inertsil ODS‐3 column (100 × 3 mm i.d., 3 µm particle size) and a mobile phase composed of formic acid and acetonitrile. Various SPE cartridges and solvents were tested in order to obtain the highest recoveries and cleanest extracts. The assay linearity of EtG was confirmed over the range from 20 to 2500 pg mg−1, with a coefficient of determination (R2) above 0.99. The lower limit of quantitation (LLOQ) was 20 pg mg−1 and the limit of detection was 10 pg mg−1. Intra‐ and inter‐day assays were less than 15% except at the LLOQ (20%). The analytical method was applied to 72 post‐mortem hair samples. EtG concentration in the hair ranged from 0 to 653 pg mg−1 hair. Copyright

Vitreous Humor as an Alternative Sample to Blood for the Supercritical Fluid Extraction of Morphine and 6-Monoacetylmorphine

The use of vitreous humor as an alternative sample to blood was investigated for the detection of heroin abuse by quantifying levels of morphine and 6-monoacetylmorphine (6-MAM) in post-mortem samples. The levels achieved in each of the two toxicological specimens were compared on a case-to-case basis to determine if a correlation existed. A total of 20 positive morphine cases were examined. In general, the levels of morphine in blood were higher than in the corresponding vitreous humor samples, with some correlation existing. 6-MAM was found in 15 blood samples and 17 vitreous humor samples. Although no correlation was found between the levels of 6-MAM in blood and vitreous humor, the latter may still be used for verification of heroin abuse.

Qualitative detection of the NSAIDs diclofenac and ibuprofen in the hair of Eurasian otters (Lutra lutra) occupying UK waterways with GC–MS

The pervasiveness of pharmaceuticals such as nonsteroidal anti-inflammatory drugs (NSAIDs) in the aquatic ecosystem through the discharge of wastewater, and their potential to biomagnify within this ecosystem, is now recognised. Residues of diclofenac and ibuprofen are currently being detected in surface waters and aquatic organisms throughout the UK and Europe. However, the levels of these residues in fish and other aquatic organisms, particularly lower trophic level prey species, have not yet been determined. While exposure to diclofenac is known to adversely affect fish, the degree to which other aquatic organisms are exposed and impacted through continuous ingestion of contaminated prey and interaction with the aquatic habitat remains unknown. The extent and effects of exposure to ibuprofen also remain largely unknown. As an exploratory subset of a broader study to investigate the detectability of diclofenac in alternative biological matrices, we analysed hair samples from Eurasian otters (Lutra lutra, n = 28) for residues of the two NSAIDs using GC–MS. The otters were collected from six counties in England as part of an ongoing otter health monitoring project at the Wildlife Veterinary Investigation Centre in Chacewater, UK. Diclofenac was qualitatively detected in five hair wash and 15 extract samples, and ibuprofen was determined to be present in at least two of the hair extract samples. Here, we provide preliminary evidence that otters are exposed to both NSAIDs and argue for further studies to identify residue loads in the otters and their prey to fully assess the pervasiveness of these compounds and potential risks of ongoing exposure to them.

Hair testing for `ecstasy' (MDMA) in volunteer Scottish drug users

The aim of the study was to compare self reported “ecstasy” use with the results of the analysis of hair harvested from the same users. Subjects were recruited by multisite chain‐referral sampling within the 1994–95 “dance scene” in Glasgow. One hundred subjects donated hair after completing a lengthy interviewer‐administered questionnaire. Overall gross concordance between self reported “ecstasy” use and discovery of MDMA (or related compounds) in analysed hair did not surpass 59%, and no relationship had a Cohens kappa of more than 0.08. Within the positive concordant dataset (n = 52), scatter was considerable, with no correlation being significant, and none more strongly positive than −0.0518. The results presented here indicate that, as far as MDMA is concerned, if judged by self‐report, hair does not reach a level of apparent accuracy that would permit its use as a general population estimator. However, hair testing is probably more reliable than self‐report, and its accuracy could be verified independently if large‐scale inter‐ and intra‐laboratory comparative research is conducted.

First detection of an NSAID, flunixin, in sheep’s wool using GC–MS

Exposure to the nonsteroidal anti-inflammatory drug (NSAID) diclofenac resulted in the near extinction of three species of Gyps vultures on the Indian subcontinent. Other NSAIDs present in the environment, including flunixin, may pose a similar risk. In the course of a study to determine the feasibility of detecting NSAIDs in keratinous matrices (i.e., hair, nails and feathers) using GC-MS, wool opportunistically collected from a sheep treated with flunixin was analysed for residues. Flunixin was detected qualitatively in external wool wash and extract samples. While residues of veterinary agents and pesticides have previously been found in sheeps wool, our preliminary investigation provides the first instance of an NSAID being detected in this matrix. Here we provide the sample preparation methods and GC-MS parameters used to enable further refinement as part of ongoing conservation and consumer quality control measures.