Determination of manganese in human brain samples

A method is presented for the determination of manganese (Mn) in human tissue samples (especially brain) by graphite furnace atomic absorption spectrophotometry (GFAAS). After complete digestion by a mixture of concentrated nitric acid (HNO₃)/concentrated perchloric acid (HClO₄) (50:50, v/v), the samples are assayed on a Perkin-Elmer 5100 PC apparatus, equipped with transversal graphite tubes and a Mn-specific hollow cathode lamp. The furnace conditions are as follows (for each step: temperature (°C)/ramp (s)/duration (s)) dry 120/1/40; char 1200/5/10; atomization 2250/0/4; pyrolysis 2400/1/1. Zeeman correction is employed. The method is linear over the range 0.05 to 5.00 μg/g wet tissue, and the limit of detection for Mn is about 0.01 μg/g wet tissue. This simple and rapid method may be of value for the post-mortem assessment of Mn accumulation in brain structures due to occupational or iatrogenic exposure. An application is presented in which elevated levels of Mn were determined in the brain samples of a 63-year-old female deceased after long-term total parenteral nutrition involving Mn supplementation.     

Analysis of elemental composition of bone tissue by the method of laser mass spectrometry to diagnose of human medico-biological characteristics

The results of analysis of elemental composition of human bone tissue by the method of laser mass spectrometry are published for the first time. This method makes it possible to detect about 20 elements of bone tissue at once. Quantitative analysis of 1 microgram/gram of an element contained in bone tissue is sufficient to diagnose of human medico-biological characteristics by this method.     

Forensic toxicological analysis of tetrahydrofuran in body materials

Routine analysis of tetrahydrofuran (THF) in biologic materials has become feasible using GC and GC/MS and the headspace method. Problems of the headspace method and this substance which has a high water- and lipid-solubility were overcome by using the salting-out technique. Identification was made by mass spectral examination, in case of concentrations over 5 micrograms per sample. For quantitative determinations, tetrahydropyran (pentamethylene oxide) was used as an internal standard in GC, and a stable isotopic substance, octadeuterated THF (TDF) in GC/SIM. THF was detected in 1 microgram per sample by GC, and 0.1 microgram per sample by GC/SIM. THF blood levels in laboratory animals reached their highest values about 1 h after the oral administration, and the half-life was about 5 h. Ratios of tissue levels to blood were ca. 1.5-2 in the adipose tissue and kidney, and fairly equal in the brain, liver, spleen, and muscle.     

Selenium determination in mother and child's hair by electrothermal atomic absorption spectrometry

A method for the selenium determination in a mother and her child's hair using palladium as a chemical modifier was optimized. The sample was digested with nitric acid and hydrogen peroxide and diluted to 5 ml. To achieve complete mineralization the samples were ashed at 1200 degrees C in the presence of palladium as a chemical modifier. The optimum atomization temperature was 1900 degrees C. The precision and accuracy of the method were studied using the reference material CRM 397. Results of calibration using aqueous standards and the standard addition method were compared. The method was applied to the selenium determination in 30 samples of the mother's and child's hair. The levels found were 0.54 +/- 0.34 microgram/g for mother's hair and 0.77 +/- 0.25 microgram/g for child's hair.     

Ethanol stability in unpreserved refrigerated antemortem blood

Ethanol stability in preserved antemortem blood has been widely studied since it is a common practice in cases involving suspected impaired driving to collect antemortem blood in evacuated blood tubes containing sodium fluoride. In some situations, antemortem blood is submitted to a forensic laboratory for ethanol analysis in evacuated blood tubes that contain only an anticoagulant. There has been limited research on ethanol stability in antemortem blood stored without a preservative. On two occasions, antemortem blood was collected from five ethanol-free individuals into 6-ml Vacutainer® tubes containing only 10.8 mg potassium EDTA. The blood tubes were spiked with ethanol to approximately either 0.08 or 0.15 g/dl. Dual-FID headspace gas chromatography was used to analyze 58 blood tubes, 29 from each session, for ethanol 1 day after sample collection and again after 1 year of refrigerated storage (~4°C). Statistically significant decreases in ethanol were detected at the 0.05 level of significance. Mean decreases in ethanol after 1 year of storage for the 0.08 and 0.15 g/dl samples were 0.013 and 0.010 g/dl, respectively. The mean ethanol decrease across all tubes was 0.012 g/dl. The range of decreases for the 58 blood tubes was 0.003–0.018 g/dl. The mean ethanol decreases measured in this unpreserved antemortem blood are comparable in magnitude to those previously observed in antemortem blood containing sodium fluoride after 1 year of refrigerated storage. Ethanol did not increase in the antemortem blood samples despite the absence of sodium fluoride.     

Sensitive and specific quantification of human genomic deoxyribonucleic acid (DNA) in forensic science specimens: casework examples.

We describe the forensic science application of a method for quantification of human genomic deoxyribonucleic acid (DNA). The two cases cited in this report involve DNA samples extracted from skin tissue and bloodstained clothing recovered from different crime scenes. High-molecular-weight DNA was recovered from both specimens, and the concentrations of these DNAs were estimated to be approximately 0.5 microgram/microL by ethidium bromide/agarose gel electrophoresis. Using the human-specific DNA probe p17H8 (locus D17Z1) to quantify the amount of human genomic DNA in these samples, it is shown that less than 1% of the DNA isolated from the skin tissue is of human origin and that the DNA isolated from the bloodstained clothing is effectively devoid of human DNA sequences. These case examples illustrate the need to quantify not only the total amount of DNA recovered from forensic casework material, but also the proportion of the DNA that is of human origin.     

Computer-aided headspace gas chromatography applied to blood-alcohol analysis: importance of online process control

This paper describes the analysis of ethanol in blood specimens from suspect drunk drivers and the associated quality assurance procedures currently used in Sweden for legal purposes. Aliquots of whole blood from two separate Vacutainer tubes are diluted with 1-propanol as internal standard before analysis by headspace gas chromatography (HS-GC) with three different stationary phases: Carbopak B, Carbopak C, and 15% Carbowax 20 M. The actual HS-GC analysis, the integration of chromatographic peaks, the collection and processing of results, as well as the quality control tests involve the use of computer-aided techniques. The standard deviation of analysis(y) increased with concentration of ethanol in the blood specimen(x), and above 0.50 mg/g the regression equation was y = 0.0033 + 0.0153x. The prosecution blood-alcohol concentration (BAC) is the mean of three separate determinations made by different laboratory technicians working independently with different sets of equipment. A deduction is made from the mean analytical result to compensate for random and systematic errors inherent in the method. At BACs of 0.5 and 1.5 mg/g, which are the statutory limits in Sweden, the allowances currently made are 0.06 and 0.09 mg/g, respectively. Accordingly, the reduced prosecution BAC is less than the actual BAC with a statistical confidence of 99.9%.     

Quantitative analysis of chlorpromazine by electron spin resonance (ESR) spectroscopy.

A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 microliters of the solution containing 0.5 microgram chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample.     

Fatal and non-fatal methomyl intoxication in an attempted double suicide

A 79-year-old man and his 73-year-old wife attempted double suicide by ingesting methomyl powder. The woman died 19 h after ingestion in spite of intensive care. At autopsy a large number of miliary hemorrhages were found in both thalami of the brain. Her husband, however, recovered after 10 days of treatment. Methomyl (CAS No. 16752-77-5, Lannate) in the biological materials was analyzed by gas chromatography-mass spectrometry. The methomyl concentration was 44 micrograms/g in the wife's serum sample collected 1 h after ingestion, and 0.2 microgram/g in the blood sample collected at autopsy. The methomyl concentration in the husband's blood sample collected 28 h after ingestion was from 0.01 to 0.1 microgram/g. It is suggested that prompt and adequate intensive care including a direct hemoperfusion is necessary to effect the recovery of patients with lethal blood levels of methomyl. The miliary hemorrhages found in the thalami of the brain are suspected to have been caused by asphyxia induced by methomyl intoxication.     

The determination of cocaine and its major metabolite, benzoylecgonine, in postmortem fluids and tissues by computerized gas chromatography/mass spectrometry

An analytical procedure for the simultaneous determination of both cocaine and benzoylecgonine in postmortem fluid and tissue samples has been developed by using computerized gas chromatography/mass spectrometry and gas chromatography using a nitrogen/phosphorus (N/P) detector. Both methods are accurate and sensitive and allow the determination of tissue concentrations of cocaine and benzoylecgonine as low as 0.015 microgram/mL.     

液液萃取-超高效液相色谱-串联质谱法测定常见食用植物油中5种鸦片生物碱

目的建立酸化甲醇(pH=3)液液萃取-超高效液相色谱-串联三重四极杆质谱(UPLC-MS/MS)测定常见食用植物油中5种鸦片生物碱吗啡、可待因、蒂巴因、罂粟碱、那可汀的检验方法。方法样品加入正己烷摇匀后用酸化甲醇(pH=3)提取,BEH C18色谱柱分离,乙腈(0.01%甲酸)-水(0.01%甲酸+0.05%氨水,体积比)梯度洗脱,电喷雾离子源正离子(ESI+)及多反应监测模式检测。结果结果显示5种待测成分在0.5~300ng/g范围内线性关系良好;方法检出限(S/N=3)在0.1~2ng/g间、定量限(S/N=10)在0.5~3ng/g间;回收率(20ng/g,200ng/g)在82.0%~101.4%间,相对标准偏差(RSD,n=6)为1.4%~4.2%,基质效应(20ng/g,200ng/g)在-5.3%~5.8%间,日间精密度为2.8%~6.7%。结论本方法前处理简单、耗时短,溶剂使用量少,灵敏度高,适合大批量常见食用植物油中5种鸦片生物碱的同时检测。     

Spectra interference between diquat and paraquat by second derivative spectrophotometry

A rapid and accurate method, combining solid-phase extraction and second-order derivative spectrophotomety approaches, is developed for the simultaneous determination of diquat (DQ) and paraquat (PQ) in blood, tissue and urine samples. Supernatant resulting from the precipitation of protein (with trichloroacetic acid) in plasma and tissue or Amberlite IRA-401 resin treated urine are passed through a mini-column packed with Wakogel gel (Silica gel). Analytes are then eluted with a non-organic solvent, 0.2mol/l HCl solution containing 2mol/l NH(4)Cl. UV spectrum of the eluent in 220-350nm range provides effective screen to detect the presence of DQ and/or PQ. In the presence of DQ or PQ alone, the analyte present is quantitated by conventional zero- or second-order derivative spectrophotometry. The calibration curve in the 0.1-5.0mg/l range for either analyte obeys Beer's law. When both DQ and PQ are present, their concentrations are determined by the peak amplitudes of their respective second-derivative spectra after the addition of alkaline dithionite reagent. Interference is negligible when the DQ/PQ concentration ratio is within the 5.0-0.2 range.Using a 2-ml of sample size, the detection limits for DQ and PQ in plasma are 0.02 and 0.005mg/l. The corresponding detection limits for urine samples (10ml sample size) are 0.004 and 0.001mg/l. Recoveries of DQ and PQ in triplicate plasma and urine samples spiked with 0.5mg/l of analytes are 93 and 85%. The precision of the proposed method resulting from triplicate study of spiked urine samples varies from 3.2 to 4.6% at 0.5mg/l of DQ and PQ, respectively.     

Identification and quantification of phenobarbital in a mummified body 10 years after death

Abstract: This article reports the determination of phenobarbital in the mummified body of a 56‐year‐old man found completely mummified 10 years after his death. When alive, he was being treated for epilepsy with phenobarbital, and the recent analyses, performed with both immunochemical techniques and gas chromatography with mass spectrometry (GC‐MS), have revealed the presence of this substance in various tissues: the mean content of barbiturate in the mummified liver tissue was 93 μg/g, 216 μg/g in the heart, 17 μg/g in the lungs, 12 μg/g in muscles, and 31 μg/g in the skin. Preliminary screening tests with immunochemical techniques to evaluate the presence of other drugs were also performed. The sample resulted negative for all substances tested. Phenobarbital can be identified and quantified thanks to its excellent chemical stability and a hypothesis of what the concentrations in the fresh tissue could have been has also been reported.     

Detection and quantification of the hypnotic zopiclone,connected with an uncommon case of drowning

A fatality, attributed to a suicidal ingestion of zopiclone and subsequent death by drowning, is described. A radioimmunoassay was performed to prescreen for the presence of the analyte. HPLC analysis with fluorescence detection demonstrated a testicular tissue concentration of 2.2 μg/g zopiclone. Further toxicological analysis revealed also the presence of diazepam in a concentration of 150 ng/g.     

Extractive alkylation and gas chromatographic analysis of sulfide

A sensitive analysis of sulfide in blood was established, using an extractive alkylation technique. Pentafluorobenzyl bromide was used as the alkylating agent, tetradecyldimethylbenzylammonium chloride as the phase-transfer catalyst, and potassium dihydrogenphosphate as the buffer to suppress the formation of sulfide. Mass fragmentography was used to identify the sulfide derivative and gas chromatography with an electron capture detector was used for quantitative determination, with the lowest limit of detection being about 0.01 microgram/g. The blood level of rats exposed to hydrogen sulfide was also determined.     

Amphetamine, cocaine and cannabinoids use among truck drivers on the roads in the State of Sao Paulo, Brazil

Lysergic acid diethylamide (LSD) is a potent hallucinogen, active at very low dosage and its determination in body fluids in a forensic context may present some difficulties, even more so in hair. A dedicated liquid chromatography-electrospray-tandem mass spectrometry (LC-ES-MS/MS) assay in hair was used to document the case of a 24-year-old man found dead after a party. Briefly, after a decontamination step, a 50mg sample of the victim's pubic hair was cut into small pieces (<1mm length), and incubated overnight in 3mL of phosphate buffer pH 5 at room temperature. After a liquid-liquid extraction (dichloromethane/ether), the extract was analyzed using a LC-ES-MS/MS method exhibiting a limit of quantification of 0.5pg/mg for LSD. A LSD concentration of 0.66pg/mg of pubic hair was observed. However, this result remains difficult to interpret owing to the concomitant LSD presence in the victim's post mortem blood and urine, the lack of previously reported LSD concentrations in hair, and the absence of data about LSD incorporation and stability in pubic hair.     

Detection of toluene in an adipoceratous body

A 24-year-old male was found dead in a car left in a river for about 3 months. The cadaver was almost adipoceratous and autopsy findings revealed that there were neither remarkable injuries nor lethal diseases. Toluene, ethanol, 1-propanol, 2-propanol, 1-butanol, dimethyl sulfide, dimethyl disulfide, isovaleraldehyde and n-butyl n-butyrate were detected in the specimens collected at the autopsy by head space gas chromatography/mass spectrometry (GC/MS). The toluene concentrations (μg/g) were 31.0 in brain, 10.6 in liver, 5.4 in kidney, 15.0 in skeletal muscle and 187.1 in adipose tissue. The presence of diatom in lung, liver and kidney suggested that death was caused by drowning. So far as we know, this is the first report of detection of toluene in an adipoceratous body.     

Determination of salvinorin A and salvinorin B in Salvia divinorum-related products circulated in Japan

Two major salvinorins, salvinorin A (SalA) and salvinorin B (SalB), in three Salvia divinorum dried leaf products and nine of its "concentrated extract" products circulated in Japan were determined. These ingredients were extracted twice with acetonitrile and decolored with graphite carbon powder. SalA and SalB were confirmed by liquid chromatography-tandem mass spectrometry in product ion scan mode, and quantified by high-performance liquid chromatography with UV detection (for SalA) and by mass spectrometry in single ion monitoring mode (for SalB). The SalA/SalB contents (mug/mg) were in the range of 3.2-5.0/0.10-0.17 in the dried leaf products and 4.1-38.9/0.26-2.42 in the "concentrated extract" products. These findings would be useful for analysis of S. divinorum-related products circulated in the drug market.     

Forensic and chemical determination of methane in cadaveric samples

Conditions were elaborated for the determination of methane, through gas chromatography, in blood and the lung by using a 2% methanol solution as an internal standard and with the below gas-chromatography column being applied: dimensions--200 x 0.3 cm, 15% di-2-ethylhexyl sebacate on Dinochrome II (0.16 x 0.21 mm) at 110 0 degree C. The detector is of the flame-ionization type. The normal content of methane was determined for blood and for the lung--0.122 +/- 0.0074 microgram/ml and 0.20 +/- 0.04 microgram/g, respectively. Biological samples from cadavers of other persons who died due to trauma were suggested for use as controls. The method was used to examine expertise objects, blood and the lung from the cadavers of peoples who died in fire.     

Comparison of ethyl glucuronide and fatty acid ethyl ester concentrations in hair of alcoholics, social drinkers and teetotallers

In previous investigations hair analysis for ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE) proved to be suitable for the detection of excessive alcohol consumption. The aim of this study was to compare EtG and FAEE concentrations in hair of alcoholics, social drinkers and teetotallers. Hair samples from 10 alcoholics in withdrawal treatment, 11 fatalities with documented excessive alcohol consumption, four moderate social drinkers who consumed up to 20 g ethanol per day, and three strict teetotallers were analysed. After external degreasing with n-heptane, extraction with a dimethyl sulfoxide/n-heptane mixture and headspace solid-phase microextraction of the extracts, four fatty acid ethyl esters (FAEEs) (ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) were analysed by gas chromatography-mass spectrometry (GC-MS) with deuterated internal standards. EtG was determined by GC-MS/NCI after ultrasonication of the samples with H2O, cleanup by SPE with aminopropyl columns and PFP derivatisation. The following concentrations were measured for the four groups: teetotallers EtG < 0.002 ng/mg, FAEE 0.05-0.37 ng/mg, moderate social drinkers EtG < 0.002 ng/mg, FAEE 0.26-0.50 ng/mg, alcoholic patients EtG 0.030-0.415 ng/mg, FAEE 0.65-20.50 ng/mg and the fatalities with alcohol history EtG 0.072-3.380 ng/mg, FAEE 1.30-30.60 ng/mg. The results confirm that by using a cut-off value of the sum of FAEE > 1 ng/mg and/or a positive EtG result in hair, excessive alcohol consumption can be identified using hair analysis. However, no significant correlation between the EtG and FAEE concentrations in the positive cases could be shown. Segmental analysis of some of the specimens did not reveal the same distribution for EtG compared to FAEE in hair, and no chronological accordance compared to the self-reported alcohol consumption could be observed for both parameters. These different results of both methods are discussed in terms of differences between EtG and FAEE in mechanism of formation and incorporation into hair and elimination from hair.