Characteristics of analytically confirmed illicit substance-using patients in the Emergency Department.

BACKGROUND/PURPOSE: Although illicit substance use-induced toxicity or complication is a frequent cause of visit to the emergency department (ED), there are limited data on cases confirmed by liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis. This study aimed to describe clinical presentations of patients who visited the ED because of acute illicit substance-related complications. METHODS: We performed a retrospective study between May 2017 and August 2018 on patients presenting to the ED with positive urine illicit substance analysis by LC-MS/MS. RESULTS: Of 203 patients with at least one illicit substance detected in their urine, 162 (79.8%) showed traditional illicit substances, and 56 (32.0%) showed new psychoactive substances (NPS). Methamphetamine was the most common illicit substance (67.9%). The most common NPS was ketamine (21.7%), followed by synthetic cathinones (14.8%). We divided patients into traditional, NPS and combined (both traditional illicit substance and NPS) groups. Polysubstance use was more common in the NPS group than in the traditional group (P < 0.001). Most patients were men (78.3%), and the average age was lower in the NPS group compared to the traditional group (P < 0.001). Although the chemical structures of cathinones are similar to that of amphetamine, 92.0% of the cathinone use cases without combination with methamphetamine use showed negative immunoassay results. CONCLUSION: Our study provided the acute illicit substance complications at ED by LC-MS/MS analysis in Taiwan. Our study showed that more than one-third cases studied were NPS users. Young adults and polysubstance users were more common among NPS users.

Determination of synthetic cathinone α-pyrrolidinovalero-phenone and its metabolite in urine using solid-phase extraction and gas chromatography-mass spectrometry.

RATIONALE: The presence of α-pyrrolidinovalerophenone (α-PVP) and its metabolites in urine is evidence of the administration of α-PVP. A toxicological challenge is that the metabolites of α-PVP exhibit amphoteric properties, which make them unsuitable for detection using gas chromatography-mass spectrometry (GC/MS). In the study reported, proper derivatization and sample extraction were essential for improving the sensitivity for GC/MS analysis. METHODS: An automated solid-phase extraction (SPE) method has been developed and optimized. The derivatization efficiency was tested using longer reaction time and the addition of polar pyridine into a mixture of N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane. Method validation, including linearity, limit of detection, precision, accuracy, and recovery, was evaluated using automatic SPE and GC/MS. RESULTS: The results suggested that adding pyridine to BSTFA (1:1, v/v) significantly improved derivatization efficiency and precision. After optimization, the linear range was from 25 to 1000 ng mL-1 with R2 > 0.9950. The limit of detection was 5 ng mL-1 for α-PVP and 25 ng mL-1 for OH-α-PVP. The recovery for SPE was over 88%. The inter-day and intra-day precisions were less than 15%. A forensic sample has been found containing α-PVP (67.3 ng mL-1 ) and OH-α-PVP (560.2 ng mL-1 ). CONCLUSIONS: This study is the first to validate an auto-SPE-GC/MS method for the quantification and qualification of α-PVP and OH-α-PVP in urine. We have successfully improved the derivatization efficiency and developed a sensitive and semi-automatic approach. This approach is desirable for the detection of synthetic cathinone at trace levels in biological samples.

Dilute-and-shoot enhances sensitivity of phthalate urinary concentrations for assessing the exposure in children.

Phthalates are not covalently bound to plastics. They can leach from experimental plastic devices. Due to the development of sensitive techniques, exogenous sources that interfere with the accuracy of phthalate monoester analysis can be easily detected. Here, we propose the simple and rapid dilute-and-shoot method to minimize sample handling and limit contact with laboratory apparatus, which efficiently reduced phthalate interferences mainly from experimental plasticware and improved the accuracy of analysis. Chemical additives in the mobile phase and modifiers in reconstituted solution were evaluated to improve peak shape and liquid chromatography separation. Under optimal conditions, the limit of detection ranged from 0.01 to 0.5 ng/mL. No phthalate monoesters were detected above the limit of detection in blank water while the leached concentrations of MMP, MEP, MiBP, MnBP and MEHP from the conventional solid phase extraction procedure were 1.9, 2.7, 0.9, 2.0 and 1.1 ng/mL, respectively. In 304 samples collected from primary school- children aged 9-10 years, we observed a positive association between body mass index (BMI) and urinary MMP and MiBP concentrations in boys, while MEOHP and MEHHP were inversely related to BMI in girls. Furthermore, detectable phthalate monoesters may be considered potential chemical obesogens related to BMI in children.