Simple and rapid detection of three amatoxins and three phallotoxins in human body fluids by UPLC-MS-MS and its application in 15 poisoning cases

Amatoxins and phallotoxins are toxic cyclopeptides found in the genus Amanita and are among the predominant causes of foodborne sickness and poisoning-related fatalities in China. This study introduces and validates a simple, rapid and cost-effective ultra-performance liquid chromatography-mass spectrometry method for the simultaneous determination and quantification of α-amanitin, β-amanitin, γ-amanitin, phallisacin, phallacidin and phalloidin in human blood and urine. Quick therapeutic decision-making is supported by a 9 min chromatographic separation performed on a Waters Acquity UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 µm) using a gradient of high-performance liquid chromatography (HPLC)-grade water and methanol:0.005% formic acid. The analyte limit of quantification was 1-3 ng/mL in blood and 0.5-2 ng/mL in urine. Calibrations curves, prepared by spiking drug-free blood and urine, demonstrated acceptable linearity with mean correlation coefficients (r) greater than 0.99 for all phallotoxins and amatoxins. Acceptable intraday and interday precision (relative standard deviation <15%) and accuracy (bias, -4.8% to 13.0% for blood and-9.0% to 14.7% for urine) were achieved. The validated method was successfully applied to analyze 9 blood samples and 2 urine samples testing positive for amatoxins and/or phallotoxins. Amatoxins and/or phallotoxins were identified in each whole blood sample at a range of 1.12-5.63 ng/mL and in two urine samples from 1.01-9.27 ng/mL. The method has the benefits of simple sample preparation (protein precipitation) and wide analyte coverage, making it suitable for emergency quantitative surveillance toxicological analysis in clinics and forensic poisoning practice.

Nontargeted screening based on EI-MS spectra using statistical methods: An investigative study of synthetic indole/indazole cannabinoids

RATIONALE

Mass spectrometry has evolved into a highly powerful tool for qualitative and quantitative chemical analyses. However, the identification of trace amounts of previously unknown structures in complex chemical matrix environments remains challenging. The rapid emergence of new synthetic cannabinoid substances is a typical example of this. Existing laboratory techniques are mostly based on methods used for lists of known illegal compounds. This situation poses a challenge to traditional data analysis and the risk of missing the compounds. Therefore, we propose to develop and validate a statistical model to classify newly emerging synthetic cannabinoid substances into a structural class or subclass.

METHODS

We obtained 70 electrospray ionization spectra of indole/indazole synthetic cannabinoids from both the actual standard analysis and the SWGDRUG mass spectral library (version 3.10). Each sample consisted of 330 m/z variables and corresponding relative intensities. We first cleared the variables with a variance below 0.1. Principal component analysis (PCA) was performed on the variance-filtered data, and the two principal components were retained to generate new data for hierarchical clustering. After hierarchical clustering, we used the receiver operating characteristic method in this cluster.

RESULTS

Seventy synthetic indole/indazole cannabinoids were classified into four clusters. The side chain of cluster 1 is mainly fluorobenzyl, cluster 2 is pentyl, cluster 3 includes compounds from several structures, and cluster 4 is mainly fluoropentyl. The most relevant characteristic ions are m/z 109, m/z 252, and m/z 253 for cluster 1; m/z 144 and m/z 214 for cluster 2; and m/z 232 and m/z 233 for cluster 4.

CONCLUSIONS

This study provides a more objective and less time-consuming solution for characterizing synthetic cannabinoids. And this work validates the ability of PCA to extract characteristic fragment ions.

Liquid chromatography with tandem mass spectrometric method for determination of 425 drugs and poisons in dried blood spots and application to forensic cases

PURPOSE

An analytical method using liquid chromatography with tandem mass spectrometry (LC-MS/MS) was established and validated for screening 425 drugs and poisons in dried blood spots (DBSs).

METHODS

Blood (20 μL) was spotted on Whatman FTA™ classic card to prepare DBS sample, then extracted with 150 μL methanol and analyzed by LC-MS/MS using a multiple reaction monitoring method.

RESULTS

The limit of detection of the compounds were 0.1-10 ng/mL. The values for recovery and matrix effect were 40.3-114.9% and 40.2-118.4%, respectively. This method was successfully applied to DBS samples from 105 humans suspected of drug poisoning, which was stored for 3-5 years at room temperature. Thirty-three kinds of drugs, including benzodiazepines, antipsychotics, antidepressants, antipyretic analgesics, non-steroidal anti-inflammatory drugs, antibiotics, antiepileptic drugs, new psychoactive drugs were confirmed in 102 cases, while no compound was detected in the other 3 cases. Estazolam, a benzodiazepine widely used in clinical practice as a sedative, hypnotic, and anti-anxiety drug, was the most frequently detected substance, occurring in 34.2% of the cases.

CONCLUSIONS

Most drugs in DBS could still be detected after storage for 3-5 years, but ambroxol, zopiclone, carbofuran, chlorpyrifos, and valproic acid were not detectable after 3-5 years of storage at room temperature. The components measured in DBS were consistent with those measured in whole blood at the collection time, thereby confirming that DBS samples have the advantage of stable storage at room temperature.

The influence of sample geometry and size on porcine aortic material properties from uniaxial tensile tests using custom-designed tissue cutters, clamps and molds

The aim of this study was to identify the influence of specimen geometry and size on the results of aortic uniaxial tensile tests using custom-designed tissue cutters, clamps and molds. Six descending thoracic aortas from pigs were used for rectangular sample tests, in which the circumferential and axial specimens had widths of 6 mm, 8 mm and 10 mm. The other six aortas were used for the dog-bone-shaped sample tests and were punched into circumferential, axial and oblique specimens with widths of 2 mm, 4 mm and 6 mm. We performed uniaxial tensile tests on the specimens and compared the test results. The results showed that mid-sample failure occurred in 85.2% of the dog-bone-shaped specimens and in 11.1% of the rectangular samples, which could be caused by Saint-Venant’s principle. Therefore, rectangular specimens were not suitable for aortic uniaxial tensile testing performed until rupture. The results also showed that the size effect of the aorta conformed to Weibull theory, and dog-bone-shaped specimens with a width of 4 mm were the optimal choice for aortic uniaxial tensile testing performed until rupture.