Development of a preparation method to produce a single sample that can be applied to both LC–MS/MS and GC–MS for the screening of postmortem specimens

A validated method for the separation of ethyl glucoside isomers by gas chromatography-tandem mass spectrometry and quantitation in human whole blood and urine

Ethyl glucoside (EG) is present in Japanese sake in high concentrations, and can be found in other alcoholic beverages like beer and wine in varying amounts. EG exists as alpha (α) and beta (β) isomers, and the concentrations and ratios of these isomers differ depending on the alcoholic beverage. Herein, we report a validated analysis method for the separation of EG isomers in human whole blood and urine, by GC-MS/MS. Whole blood and urine samples were deproteinized and interferences removed by weak cation exchange cartridges. The target analytes were acetylated using acetic anhydride and pyridine by microwave-accelerated derivatization. Separation was performed using tandem columns, with detection in the multiple reaction monitoring (MRM) mode. The MRM transitions for all compounds were m/z 157.0 > 115.1 for the quantifying transition, and m/z 157.0 > 73.1 and m/z 141.0 > 81.0 for the qualifying transitions. Assay validation included linearity, LOD and LLOQ, bias, within-run and between-run precision, stability, and dilution integrity. Baseline separation of the 2 isomers was achieved with linear calibration (r² > 0.99) across the calibration range 0.625 to 50 μg/mL for both α- and β-EG in both whole blood and urine. The validated method was then applied to actual human whole blood and urine samples collected at autopsy, as well as relevant alcoholic beverage samples. The quantitation of EG isomers could benefit the forensic toxicology community by acting as markers for recent alcoholic beverage consumption.

Assessment of Triage DOA®, Status DS10, and DRIVEN-FLOW® M8-Z on-site drug screening kits for postmortem urine

Based on the screening results of mass analyses using gas chromatography- mass spectrometry (GC-MS) and liquid chromatograph-tandem mass spectrometry (LC-MS/MS), we assessed the performance of Status DS10 (Status) and DRIVEN-FLOW® M8-Z (DF8), and compared the results with those of Triage DOA® (Triage) using 356 autopsy urine samples within one month of death. The sensitivity to benzodiazepines was 0.52 in Triage, 0.59 in Status, and 0.58 in DF8 with few false-positive cases. Triage detected triazolo-derivatives more easily than DF8. DF8 detected diazepam and nitro-benzodiazepines more easily than Status and Triage, with Status performing better than Triage. However, lorazepam detection with Status was difficult. There were 11 false-positive cases for amphetamines in Triage and 12 for Status-AMP at more than one week after death, but there were no false-positive in Status-MET and DF8. Tricyclic antidepressant (TCA) was detected in five cases by mass analysis, while there were 6 false-positive cases in Triage and 10 in both Status and DF8. In the TCA false-positive cases, tricyclic psychotics such as quetiapine, chlorpromazine, and carbamazepine existed. There were 23 true-positive and 6 false-positive cases for zolpidem in DF8 without false-negative cases. The accuracy of Status and DF8 for barbiturates or opiates was almost 1, but Triage was 0.98. There were no samples containing cocaine, THC, phencyclidine, or methadone. Based on the above, we conclude that Status and DF8 are comparable or slightly better than Triage, with fewer false-positive and fewer false-negative cases, except for TCA.

A comparative study of pleural effusion in water area, water temperature and postmortem interval in forensic autopsy cases of drowning

Japan is surrounded by the sea and is also a mountainous country with many rivers. Japan has the second- highest rate of deaths caused by drowning in the world. Pleural effusion (PE) is one of the major findings at autopsy. It is found in approximately 80% of drowning mortalities and is observable for a relatively long postmortem interval (PMI). We focused on the amount of pleural fluid in drowning cases, discussed the relationship of PE with the drowning environment, water temperature, and postmortem interval, and established more simple and practical criteria for the diagnosis of drowning. We measured the weight of the lungs, PE, and their sum as the intrathoracic (IT) weight (total weight of lungs + pleural effusion), and calculated the PE ratio [(PE weight/IT weight) × 100]. A total of 130 drowning deaths diagnosed through forensic autopsies were investigated in this study. The cases were classified by drowning environment (freshwater, brackish water, and seawater), water temperature (under 20 °C, more than 20 °C), and postmortem interval (less than 1 day, 1–3 days, more than 3 days). The present study demonstrated that the PE ratio may be more effective for the diagnosis of drowning. Moreover, the accumulation of PE is affected by drowning environment, water temperature, and PMI. Collectively, it is important to assess the PE ratio and consider these factors in autopsy cases of victims found in water.

Efficacy of DRIVEN-FLOW® M7-II, a new on-site drug screening kit in postmortem urine compared with Triage DOA®

The efficacy of DRIVEN-FLOW® M7-II(DFM7II) for seven drug groups was compared with Triage DOA® (Triage) using 340 autopsy urine samples taken from bodies within 1 month of death based on mass screening analysis of GC/MS and LC-MS/MS. The sensitivity to benzodiazepines was 0.56 in Triage and 0.53 in DFM7II with few false positives, and their accuracy was 0.88. Triage detected triazolo diazepine derivatives more easily than DFM7II. DFM7II detected diazepam and nitro benzodiazepines more easily than Triage. There were nine amphetamine false-positive cases of more than 10 days after death in Triage, but these were absent in DFM7II during this period. The accuracy of amphetamines for Triage was 0.96 and for DFM7II was 1. Tricyclic antidepressant (TCA) was detected in five cases by mass analysis, while there were four false-positive cases using Triage and eight cases using DFM7II. In the TCA false-positive cases of both kits, tricyclic psychotics such as chlorpromazine, carbamazepine, and quetiapine were included as well as the drug poisoning cases. There were no samples containing cocaine or THC. The accuracy of DFM7II for opiate and barbiturates was 1, but those of Triage was less than 1. Based on the above, DFM7II is a more accurate kit with fewer false-positives for target drug groups, other than TCA, than Triage.

An in-house centrifugation and membrane filtration technique for identifying microorganisms from positive blood culture bottles with high identification rates using matrix-assisted laser desorption ionization-Time-of-flight mass spectrometry: A preliminary report

Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most promising technologies for the identification of microbial pathogens directly from positive blood culture bottles. As blood culture bottle medium contains various nonbacterial proteins, including those derived from blood cells, pretreatment to effectively remove host cells is key for successful proteome-based identification of microorganisms. Although the Sepsityper® kit is the most widely used pretreatment protocol, its performance is not satisfactory, particularly for gram-positive isolates. We developed a new in-house protocol, the centrifugation and membrane filtration technique (CMFT), in which vacuum-filtration is coupled with differential centrifugation. We prospectively evaluated the performance of this novel method compared with that of the Sepsityper®. For gram-negative bacterial isolates, the species-level identification rates obtained with the CMFT and the Sepsityper® were comparable (98.8% vs 92.9%). By contrast, for gram-positive isolates, the performance of the CMFT was significantly better than that of the Sepsityper® (P < 0.05). Using our new protocol, 81 (95.3%) isolates were identified with a score >2.0, and 85 (100%) isolates were identified with a score >1.7, versus 46 (54.1%) and 69 (81.2%), respectively, for the Sepsityper®. These results are preliminary, but considering that this novel protocol provides notably high species-level identification rates for gram-positive isolates, it deserves assessment in a larger-scale study with a variety of platforms for MS-based identification of microorganisms.

A fast and simple approach for the quantification of 40 illicit drugs, medicines, and pesticides in blood and urine samples by UHPLC-MS/MS

A fast and simple approach to overcome challenges in emergency toxicological analysis, using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) has been developed, for the detection of analytes in blood and urine samples from the following drug classes: analgesics, benzodiazepines, antidepressants, anticonvulsants, drugs of abuse, and pesticides. These substances are relevant in the context of emergency toxicology in Brazil. The sample preparation procedure was relatively easy and fast to perform. The method was fully validated giving limits of in the range of 0.5 and 20 ng mL^-1 for blood and urine samples. The intraday and interday precision and accuracy were considered adequate for all analytes once the relative standard deviation (RSD) (%) was lower than 20% for quality control (QC) low and lower than 15% for CQ medium and high. The developed method was successfully applied to 320 real samples collected at the Poison Control Center of São Paulo, and 89.1% have shown to be positive for some of the analytes. This confirms its applicability and importance to emergency toxicological analysis, and it could be very useful in both fields of clinical and forensic toxicology.

Determination of 12 commonly found compounds in DUID cases in whole blood using fully automated supported liquid extraction and UHPLC-MS/MS

A high-throughput UHPLC-MS/MS method for the most frequently found compounds; tetrahydrocannabinol (THC), amphetamine, methamphetamine, MDMA, clonazepam, diazepam, nordiazepam, oxazepam, alprazolam, nitrazepam, morphine, and codeine, in driving under the influence of drugs (DUID) cases in whole blood, is presented. Automated sample preparation by 96-well supported liquid extraction (SLE) plates with ethyl acetate + heptane (80 + 20, v/v) as organic solvent was carried out on a Freedom Evo 200 platform from Tecan. An aliquot of 100 μL whole blood was used. Sample preparation time for 96 samples was 1.5 h. Compounds were separated with gradient elution on a C₁₈ column (50 × 2.1 mm, 1.7 μm) with a mobile phase consisting of 5 mM pH 10.2 ammonium formate and methanol. The run time was 4.5 min and 1 μL was injected on an Acquity UPLC I-Class system with a Xevo TQS tandem-quadrupole mass spectrometer in multiple-reaction monitoring mode (MRM) from Waters. Isotope labelled, ¹³C, internal standards (ISs) were used for all compounds except for alprazolam and morphine, which had deuterated analogs. Quantification was carried out with calibrators without whole blood matrix. Full validation was carried out according to international guidelines, and a new approach for evaluation of process efficiency (PE) has been presented. Linear or quadratic weighted (1/x) calibration curves were used with R² ≥ 0.999. The method showed satisfactory deviations ±16% when compared to the existing methods, and satisfactory agreement with proficiency testing control samples (z-score -1.6 to 1.8, n = 16 samples). The precision, estimated as the relative standard deviation (RSD) of the concentration difference between results from two independent analyses of authentic whole blood samples, was ≤7.2% in antemortem and ≤9.3% in postmortem samples. Recovery was ≥85% for all the compounds, except morphine ≥62% and THC ≥ 50%. PE was satisfactory for all the compounds with low variation in IS response, RSD ≤ 16% (THC 27%) in antemortem samples and ≤34% (THC 66%) in postmortem samples. To the best of our knowledge, this is the first automated 96-well SLE UHPLC-MS/MS method developed for the simultaneous determination of these 12 compounds in whole blood covering the concentration ranges found in forensic samples. The method has been used in routine work during the last ten months, analysing about 9900 antemortem and 1000 postmortem whole blood samples, and has proven to be robust and reliable.