Drug Testing and Analysis最新文献

Homicide, suicide, or accident - elemental intoxication may be a cause in each of these types of deaths. Inductively coupled plasma mass spectrometry (ICP-MS) has emerged as the gold standard analytical method for toxic metal analysis in both clinical and forensic settings. An ICP-MS method was developed using a modified acidic workup for the quantitative determination of arsenic, lead, and thallium. Method validation focused on the assessment of linearity, between- and within-day precisions, limits of detection (LoD) and lower limits of quantification (LLoQ), and carryover. The method was applied to analysis of postmortem peripheral blood samples from 279 forensic cases for which orders for chemical-toxicological examination had been received from the public prosecutor's office. Using six-point and one-point calibrations (latter for rapid screening purposes), precisions and accuracies ranged from -4.8 to 5.8% and -6.4 to 7.5%. Analytical sensitivities for As, Pb, and Tl were 0.08, 0.18, and 0.01 μg/l (LoD) and 0.23, 0.66, and 0.03 μg/l (LLoQ), respectively. Observed postmortem peripheral blood concentrations were As, 1.31 ± 3.42 μg/L; Pb, 17.4 ± 13.1 μg/L; and Tl, 0.11 ± 0.07 μg/L (mean ± standard deviation [SD]). Elemental concentrations, determined in additional quality control samples, were in good agreement to those obtained with an external ICP-MS method based on alkaline sample processing. The current method is practicable and compatible with an ICP-MS system used for trace element analysis in an accredited medical laboratory. It allows for implementation of low-threshold investigations when metal intoxications are suspected in forensic routine.

Small peptide hormones are widely used in sports as performance-enhancing substances, making it crucial to develop sensitive analytical methods for their detection in doping control analysis. Various factors significantly affect analytical sensitivity, such as the selection of ultra-performance liquid chromatography (UPLC) mobile phase, high-resolution mass spectrometry (HRMS) scanning modes, and extraction solvents for pretreatment. Herein, comparative study approach was utilized to investigate the sensitivity of each peptide analyte under both full scan and parallel reaction monitoring (PRM) modes of HRMS and assess the effects of some protein precipitants as a part of extraction solvents on solid-phase extraction (SPE). The results showed that full scan should be selected as the primary scan mode of HRMS, and the combination with PRM mode could effectively compensate for the limitations of full scan, and the addition of protein precipitants would adversely affect the detection of certain small peptide analytes. Meanwhile, influences of ammonium formate in reverse UPLC mobile phase on the charge state distribution of small peptides were investigated and elucidated. Based on these findings, a sensitive and reliable UPLC-HRMS analytical method combining full scan and PRM mode was validated for screening and confirmation of 63 small peptide analytes after SPE, with limits of detection (LODs) ranging between 0.010 and 0.473 ng/ml and limits of identification (LOIs) ranging between 0.015 and 1.512 ng/ml. Additionally, suggestions were provided for the detection of [Arg8]-vasopressin, dermorphin, and its analogues.

Nails are a keratinized matrix that has been proposed as an alternative to hair to evaluate long-term and retrospective consumption of drugs of abuse and pharmaceuticals. This matrix has been gaining interest in recent years, with new studies focusing on the analysis of fingernails and/or toenails for different substances. However, nails and hair present differences in structure, growth, and incorporation pathways that may affect drug incorporation and analysis and complicate the interpretation of the results. To better understand the results in nail samples, a comparison of concentrations found in hair, fingernails, and toenails has been described in the literature for some drugs. This review unifies the results found in the literature, with special interest on studies that report paired samples from the same individuals. Differences between fingernail and toenail samples, as well as proposed cut-offs in nails, are also discussed. Definite conclusions can be reached for some drugs, but, in general, more standardized studies are needed to better understand nail results.

Gene doping is prohibited in horse sports and can involve the administration of exogenous genes, called transgenes, to postnatal animals. Quantitative polymerase chain reaction (qPCR) methods have been developed to detect gene doping; however, these generally require DNA extraction from the plasma prior to qPCR. In this study, we developed two methods, direct droplet digital PCR (ddPCR) and nested ddPCR, to detect the equine erythropoietin (EPO) transgene without DNA extraction. Direct ddPCR used pretreated plasma and PCR to detect the EPO transgene spiked at 10 copies/μL. Nested ddPCR utilised pre-amplification using nontreated plasma, purification of PCR products and PCR to detect the EPO transgene spiked at 1 copy/μL in plasma. These methods successfully detected the EPO transgene after intramuscular injection into horses. Since each method has different detection sensitivity, the combined use of direct ddPCR for screening and nested ddPCR for confirmation may complement each other and prevent the occurrence of false positives, allowing the reliable detection of gene-doped substances. One advantage of these methods is the small amount of sample required, approximately 2.2-5.0 μl, owing to the lack of a DNA extraction step. Therefore, these tests could be applied to small volume samples as an alternative to conventional gene doping tests.

Olanzapine (OLZ), a second-generation antipsychotic drug, is effective in the treatment of acute psychosis, schizophrenia, agitation, bipolar mania, and other psychiatric problems. Antipsychotics are prescribed drugs, which lead the drug abuser to illegal methods of access. This behavior also demonstrates the association of OLZ with criminal involvement, commonly observed at forensic crime scenes. The acute toxicity and even death resulting from OLZ exposure have been highlighted in numerous studies. Therefore, developing analytical techniques to detect OLZ is essential for forensic toxicology. This study aimed to develop a specific and reliable LC-MS/MS method for OLZ detection and quantification in hair samples. The method was validated in terms of selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), trueness, precision, and uncertainty. The range of linearity was between 0.1-100 ng/mg, with LOD and LOQ values established at 0.036 ng/mg and 0.1 ng/mg, respectively. All validation results are within acceptable parameters. The validated method has been applied to authentic hair samples. The variation of OLZ concentrations in 12 hair segments (2 from Case 1 and 10 from Case 2) from two drug-positive patients, ranging from 0.131 to 0.460 ng/mg, is presented in this study. Although several studies have been conducted to determine OLZ in hair samples using segmental analysis via hair solubilization, this study is the first to determine OLZ in hair samples after "digestion" with comparative parameters prior to chromatographic analysis.

Hair analysis is a powerful tool to assess drug use, yet the challenge of external contamination complicates its interpretation. Understanding the influence of cosmetic hair treatments is pivotal as their presence may affect this phenomenon. This study investigated the effects of four cosmetic treatments (bleach, henna, gel, and dry shampoo) on the external in vitro contamination of cocaine and its primary metabolite, benzoylecgonine (BE). Hair samples were divided into four groups: A-hair treated with cosmetics then contaminated; B-hair contaminated then subjected to cosmetic treatment; and C-hair solely contaminated (control group). Negative hair samples (n = 24) were immersed in a cocaine and BE aqueous solution of 1 μg/mL for 24 h. All hair samples were analyzed by a LC-MSMS procedure successfully validated according to ANSI/ASB Standard 036 guidelines (limit of quantification at 10 pg/mg). Henna in Group A (n = 13) resulted in the most substantial reduction for cocaine (92%), while bleach in Group B (n = 15) showed an 80% decrease. For BE, Group A henna (n = 13) exhibited a 50% reduction, and Group B bleach (n = 15) demonstrated a 71% decrease, all compared to Group C (n = 24). The study found no significant differences concerning hair color (black (n = 3), brown (n = 10), red (n = 5) and blond (n = 6)) or shape (straight (n = 6), wavy (n = 16), curly (n = 1), and coily (n = 1)). All analysis were performed in triplicate with variations below 20%. These findings emphasize that cosmetic treatments do affect cocaine/BE concentrations in hair when exposed to external contamination, highlighting the importance of considering an individual's cosmetic history prior to interpretation.

The ability of Electronic Nicotine Delivery Systems (ENDS) to deliver nicotine is central to their function to substitute for cigarettes, allowing people who smoke to switch away from smoking, thus reducing their exposure to harmful chemicals in cigarette smoke. The nicotine concentration in ENDS e-liquid has proved to be a poor predictor of nicotine uptake in users. Using meta-analytic methods to analyze 12 pharmacokinetic studies of nicotine-salt closed-system ENDS, this paper examines whether the mass of nicotine/puff of aerosol can predict C_max in pharmacokinetic studies. C_max values were available for 38 products, in 58 use conditions (including both controlled [3 s] and ad libitum puffing), comprising 1769 participant observations. Nicotine/puff data reflected chemical analyses of aerosol obtained under nonintense (3 s) or intense (6 s) machine puffing. Meta-regression analyses (weighted by reliability of C_max estimate) assessed the relationship of nicotine/puff to C_max. In some models, empirical data were used to impute the variation in C_max or the nicotine/puff value under intense puffing. In simple linear models, C_max was significantly associated with nicotine/puff under all combinations of intense/nonintense and controlled/ad-libitum conditions, with R² values of 0.71-0.77. More complex models based on quadratic effects or log[nicotine/puff] did not generally improve upon more parsimonious linear models. Application of the model illustrates the divergence between nicotine concentration in e-liquids and expected C_max when other ENDS parameters vary. The meta-analytic model may have utility in settings where clinical pharmacokinetic data are not available, including product development.