Journal of analytical toxicology最新文献

Occasionally, obtaining an adequate or acceptable postmortem blood specimen for drug analysis is not possible due to factors such as decomposition, exsanguination, or embalming. Submandibular salivary gland tissue, one of three major types of salivary gland tissue in the oral cavity of humans, has been reported to be a viable alternative postmortem specimen for toxicological testing. In this study, we evaluated the performance of the Randox Evidence Investigator instrument and Randox DOA (Drugs of Abuse) Ultra Whole Blood Array for the semi-quantitative determination of 21 immunoassays in an alternative matrix, submandibular salivary gland tissue. We analyzed 132 submandibular salivary gland tissue specimens and compared the generated results to concomitantly collected postmortem whole blood specimen results. Oxycodone 2, meprobamate, barbiturate, benzodiazepine assay 1, zolpidem, and buprenorphine all showed perfect agreement (Cohen's kappa score = 1.00) between the submandibular salivary gland tissue results and the postmortem whole blood results; dextromethorphan, fentanyl, benzoylecgonine, methamphetamine, tricyclic antidepressants, oxycodone 1, and opiate showed an almost perfect agreement (Cohen's kappa score = 0.81-0.99); methadone, generic opioids, and amphetamine exhibited substantial agreement (Cohen's kappa score = 0.61-0.80). Tramadol demonstrated fair agreement (Cohen's kappa score = 0.41-0.60). The lowest measure of agreement was observed with cannabinoids, meeting criteria for slight agreement (Cohen's kappa score = 0.01-0.20). An application of the techniques described in this study could be implemented in postmortem toxicology laboratories as well as medical examiners offices to provide preliminary drugs of abuse test results that can be used to direct additional testing. This study highlights the successful integration of a novel specimen matrix and an "off-label" use of an established analytical technique.

Diphenhydramine has been available for decades in non-prescription formulations for the treatment of allergic reactions, insomnia and symptomology associated with colds. In addition, dimenhydrinate, a precursor to diphenhydramine, is available in preparations for the treatment of nausea and vomiting. Diphenhydramine and other first-generation antihistamines are being replaced by second- and third-generation antihistamines which are associated with fewer side effects, notably the lack of drowsiness; however, there are still a variety of therapeutic uses that have persisted in both adults and children. In this study, postmortem blood concentrations of diphenhydramine were determined, by liquid chromatography tandem mass spectrometry, in seven children with concentrations ranging from 0.051 to 2.6 mg/L. The cause of death in two cases was attributed, at least in part, to diphenhydramine toxicity while diphenhydramine detection in five cases was considered incidental to the cause of death.

The long-term stability of drug concentrations in human plasma samples when stored under normal laboratory conditions over several years is important for research purposes and clinical re-evaluation, but also for forensic toxicology. Fifty human plasma samples from a former clinical trial were re-analyzed after storage at -20°C for 11 years. Plasma samples were extracted using solid-phase extraction. Isotope labelled sufentanil-D5 was used as internal standard. Sufentanil plasma concentrations were determined by ultra-performance liquid chromatography (UPLC) with gradient elution, followed by tandem mass spectrometry with electrospray ionization. The linear dynamic range (LDR) was 25 - 2500 pg/mL, the limit of detection was 10 pg/mL, and the lower limit of quantification was 25 pg/mL. Intra- and inter-assay error did not exceed 6%. The deviation of the measured sufentanil plasma concentrations between the reanalysis and the first analysis was -63 ± 14% (mean ± SD). Therefore, sufentanil concentrations in human plasma were not stable in samples frozen at -20°C over 11 years.

The identification of novel psychoactive substances (NPSs) in casework at the Los Angeles County Department of Medical Examiner (LACDME) is constantly evolving. The case detailed herein marks the first detection of metonitazene in forensic casework at the LACDME which occurred in August 2023. Furthermore, bromazolam was found in the decedent's system and both substances were identified in drug evidence collected at the death scene. No other drugs were detected and the manner and cause of death were determined as accidental due to effects of bromazolam and metonitazene. The concentrations detected were 1.6 ng/mL and 4.4 ng/mL of metonitazene in the jugular blood and femoral blood, respectively, and 93 ng/mL of bromazolam in the femoral blood. Constraints in screening techniques conducted by toxicology laboratories create challenges in which numerous NPSs available on the illicit drug market can go undetected. Even if labs detect an NPS in their screening methodology, confirmation methods might not cover every NPS, given the impracticality of labs keeping pace with validations as new NPSs emerge in casework. The significance of testing medical evidence collected at death scenes by drug chemistry analysis becomes crucial when initial toxicology results are negative. In cases where there is evidence of potential drug paraphernalia this is especially true as it can be pivotal in determining the cause and manner of death.

Aim: This study focused on the simultaneous detection of amphetamine, 3,4-methyl enedioxy methamphetamine, morphine, benzoylecgonine, and 11-nor-9-carboxy- tetrahydrocannabinol (Δ9-THC-COOH) in whole blood and DBS. It is aimed to select a solvent mixture for liquid-liquid extraction (LLE) technique employing LC-MS/MS. The obtained DBS results were compared with the whole blood samples results.

Methods: A simple, rapid, and reliable LC-MS/MS method was developed and validated for all analytes in whole blood and DBS. LC was performed on a Hypersil Gold C18 column an initial step with a gradient of 0.01 % formic acid, 5 mM ammonium format buffer in water, and acetonitrile at 0.3 ml/min with 7.5-min runtime.

Results: A methanol:acetonitrile (40:60 v/v) mixture was selected for both matrices. LOQ values were 10-25 ng/mL; linear ranges were LOQ-500 ng/ml for all analytes; correlation coefficients were greater than 0.99, and all calibrator concentrations were within 20%. Analytical recovery in blood and DBS ranged from 84.9-113.2% of the expected concentration for both intra and-inter day. Analytes were stable for 1, 10, and 30 days after three freeze/thaw cycles. It was determined that the variances of the results obtained with the two matrices in the comparison study were equal for each analyte, and the results were highly correlated (r=0.9625).

Conclusion: A sensitive, accurate, and reliable chromatographic method was developed to determine amphetamine, MDMA, morphine, benzoylecgonine, and cannabis, by performing the same preliminary steps with whole blood and dried blood spots. It was observed that the results obtained in these two matrices were compatible and interchangeable when statistically compared.