A Fatal Case of Gas Intoxication in Silage Pit.

Fatalities due to gas intoxication are rare in routine forensic casework. The most common gas is carbon monoxide, with other gases (ammonia, methane, propane and butane, carbon dioxide, hydrogen sulfide) encountered only very rarely. In this report, we describe the accidental death of two maintenance workers who were found in the silage pit at a biogas plant. The autopsy revealed signs of asphyxia in both the deceased. Analysis of the gaseous mixtures in the tank using an infrared gas analyzer showed slightly elevated concentrations of carbon dioxide. Toxicological examination of the blood of both the deceased using gas chromatography with a flame ionization detector, spectrophotometry and liquid chromatography-mass spectrometry did not detect any toxicologically significant substance that would explain the sudden collapse. Both the autopsy and the toxicology analyses suggest CO2 intoxication as the most likely cause for the collapse of the two men, which then led to sudden asphyxia.

Simultaneous determination of designer benzodiazepines in human serum using non-aqueous capillary electrophoresis - Tandem mass spectrometry with successive multiple ionic - Polymer layer coated capillary.

A novel non-aqueous capillary electrophoresis - tandem mass spectrometry method for the simultaneous separation, identification and quantification of nine designer benzodiazepines (bentazepam, etizolam, deschloroetizolam, diclazepam, flubromazepam, flubromazolam, nimetazepam, phenazepam, and pyrazolam) was developed. A non-aqueous running electrolyte consisting of 25mM ammonium acetate with 100mM trifluoroacetic acid in acetonitrile was used. The separation was carried out using a semipermanent coated capillary (successive multiple ionic-polymer coating) with a strong anodic electroosmotic flow at a negative separation voltage within twelve minutes. Electrospray ionization with a triple quadrupole mass spectrometry was utilized for the identification and quantification of selected designer benzodiazepines in a positive ionization mode. The developed method was validated and applied on the analysis of spiked serum sample following a simple liquid-liquid extraction. The LODs of the designer benzodiazepines were between 1.5 and 15.0ngmL-1.

Heart rate is a useful marker of adherence to beta-blocker treatment in hypertension.

OBJECTIVES: Suboptimal medication adherence is common among patients with hypertension. Measurements of plasma or urinary levels of antihypertensive drugs are useful, but not widely available. The aim of our study was to investigate the relation of patients' heart rates to their serum beta-blocker levels. METHODS: We correlated 220 measurements of serum beta-blocker levels in 106 patients with apparently resistant hypertension to their corresponding office heart rate. A significant proportion, 44.6% of patients, were non-adherent to beta-blocker treatment according to serum level measurement. Non-adherent patients had significantly higher heart rates (80.9 vs. 66.6 bpm, p < .001), systolic (157.4 vs. 147.0 mm Hg, p = .002) and diastolic blood pressure (91.1 vs. 87.2 mm Hg, p = .041) in comparison to adherent patients. RESULTS: Heart rate above 75.5 beats per minute predicted non-adherence to beta-blocker treatment with a sensitivity of 62.5%, specificity 86.8% and AUC ROC 0.802 (p < .001). Higher heart rate cutoff might be applicable for nebivolol but was not determined due to the low number of patients treated with nebivolol. CONCLUSIONS: We concluded that heart rate was shown to be a good predictor of non-adherence to beta-blocker treatment, and might become a quick and easy measure to determine patient adherence in hypertensive patients.

Analysis of selected designer benzodiazepines by ultra high performance liquid chromatography with high-resolution time-of-flight mass spectrometry and the estimation of their partition coefficients by micellar electrokinetic chromatography.

A new ultra high performance liquid chromatography with electrospray ionization time of flight mass spectrometry method for the selective and sensitive separation, identification, and determination of selected designer benzodiazepines (namely, pyrazolam, phenazepam, etizolam, flubromazepam, diclazepam, deschloroetizolam, bentazepam, nimetazepam, and flubromazolam) in human serum was developed. The separation of the studied designer benzodiazepines was achieved on C18 chromatographic column using gradient elution within 6 min without any significant matrix interferences. Liquid-liquid extraction with butyl acetate was applied for serum samples cleanup and preconcentration of studied designer benzodiazepines. The method was validated in terms of linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery, and sample stability. The limit of detection values were 0.10-0.15 ng/mL. The method was applied to a spiked serum sample to demonstrate its applicability for systematic toxicology analysis. Furthermore, a capillary chromatographic method with micellar electrokinetic chromatography was used for the estimation of partition coefficients of studied designer benzodiazepines as important parameters to evaluate their pharmacological and toxicological properties.

Fast and sensitive analysis of beta blockers by ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry.

This paper presents a method for the determination of acebutolol, betaxolol, bisoprolol, metoprolol, nebivolol and sotalol in human serum by liquid-liquid extraction and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. After liquid-liquid extraction, beta blockers were separated on a reverse-phase analytical column (Acclaim RS 120; 100 × 2.1 mm, 2.2 µm). The total run time was 6 min for each sample. Linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery and sample stability were evaluated. The method was successfully applied to the therapeutic drug monitoring of 108 patients with hypertension. This method was also used for determination of beta blockers in 33 intoxicated patients.

Simultaneous determination of mushroom toxins α-amanitin, ß-amanitin and muscarine in human urine by solid-phase extraction and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry.

This paper presents a method for the simultaneous determination of α-amanitin, ß-amanitin and muscarine in human urine by solid-phase extraction (SPE) and ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. The method can be used for a diagnostics of mushroom poisonings. Different SPE cartridges were tested for sample preparation, namely hydrophilic modified reversed-phase (Oasis HLB) and polymeric weak cation phase (Strata X-CW). The latter gave better results and therefore it was chosen for the subsequent method optimization and partial validation. In the course of validation, limits of detection, linearity, intraday and interday precisions and recoveries were evaluated. The obtained LOD values of α-amanitin and ß-amanitin were 1ng/mL and of muscarine 0.09ng/mL. The intraday and interday precisions of human urine spiked with α-amanitin (10ng/mL), ß-amanitin (10ng/mL) and muscarine (1ng/mL) ranged from 6% to 10% and from 7% to 13%, respectively. The developed method was proved to be a relevant tool for the simultaneous determination of the studied mushroom toxins in human urine after mushroom poisoning.

Capillary electrophoresis determination of thiopurine methyl transferase activity in erythrocytes.

Thiopurine S-methyltransferase (TPMT) catalyzes methylation of thiopurine drugs (e.g. 6-mercaptopurine, azathioprine). Decreased activity of TPMT is associated with hematopoietic toxicity after administration of standard doses of the drugs. We developed capillary electrophoretic method for determination of TPMT enzyme activity in erythrocytes. Limit of quantification of the method is 1.5 micromol/L (S/N=6). The recovery of 6-methylmercaptopurine was 87.5-94.8%, imprecision value (as CV, n=10) was 1.68% (within-day) and 2.53% (between-day). Erythrocyte TPMT activities were measured in 60 healthy adult volunteers.

Capillary electrophoretic method for nucleotide analysis in cells: application on inherited metabolic disorders.

Purine and pyrimidine nucleotides influence many metabolic pathways and their analogs have been widely used in medicine. A capillary electrophoretic method was developed for measuring intracellular nucleotides. The final BGE consisted of 40 mM citric acid with addition of 0.8 mM CTAB titrated by gamma-aminobutyric acid to pH 4.4. The electrophoretic separations were carried out in an uncoated silica capillary (id/od - 75/375 microm; effective/total length - 90/97 cm). The method allows a complete separation of 21 nucleotides and deoxynucleotides within 15 min with separation efficiencies up to 400,000 theoretical plates per meter. Due to the use of an acidic separation medium, the method offers a high selectivity toward the studied analytes versus possible interferences from matrices. Sample preparation was optimized in order to shorten work-time and prevent analyte degradation. The method was applied for analyzing nucleotides in human erythrocytes and Chinese hamster ovary cells. Diagnostic potential for inherited metabolic disorders of nucleotide metabolism is presented.