Determination of venlafaxine in post-mortem whole blood by HS-SPME and GC-NPD.

Venlafaxine is a phenethylamine derivative widely prescribed for the treatment of depression which inhibits both serotonin and norepinephrine reuptake (SNRI). In treatment with antidepressants of patient with depression and other psychiatric disorders there is also increased risk of suicidal thought and behaviour. Several lethal intoxications involving venlafaxine usually among psychotic patients have been reported in the literature. Sample preparation is of the greatest significance for a successful toxicological analysis. The development of simple, effective and rapid extraction procedures of drugs from post-mortem biological samples is a challenge. Headspace-solid phase microextraction (HS-SPME) offers significant advantages such as simplicity, low cost, compatibility with analytical systems, automation and solvent-free extraction. The aim of our work was the optimization of a HS-SPME procedure for the determination of venlafaxine in post-mortem biological samples by gas chromatography (GC) with nitrogen-phosphorous detection (NPD). Venlafaxine was extracted on 100 µm Polydimethylsiloxone Coating-Red (PDMS) SPME fiber and determined by GC-NPD. Salt addition, extraction temperature, preheating and extraction time were optimized to enhance the recovery of the extraction from aqueous solution spiked with venlafaxine. Finally the developed procedure was applied to post-mortem biological samples of a fatally poisoned woman by venlafaxine. The drug was quantified in post-mortem blood gastric and oesophagus contents of the deceased woman. A simple and rapid procedure using HS-SPME was developed for sample preparation of venlafaxine in post-mortem biological samples prior to GC-NPD determination. Validation data was satisfactory, thus enabling application in the toxicological analysis of forensic samples.

Solid phase microextraction applied to the analysis of organophosphorus insecticides in fruits.

Trace amounts of organophosphorus pesticides (OPs) were determined in various fruits by headspace solid phase microextraction (HS-SPME) and gas chromatography-nitrogen phosphorous detection (GC-NPD). Sampling from the headspace enhanced method selectivity, whereas at the same time improved fiber life time and method sensitivity. Diazinon, parathion, methyl parathion, malathion and fenithrothion were determined in various fruits: more than 150 samples of 21 types of fruits were studied. SPME-GC-NPD provided a useful and very efficient analytical tool: method linearity ranged from 1.2 to 700 ng/ml. Limits of detection (LODs) and quantitation (LOQs) ranged from 0.03 to 3 ng/ml and 0.12 to 10 ng/ml respectively, values well below the residue limits set by the EU. Less than 2% of the samples were found positive containing amounts higher than the EU limits. The effect of fruit peeling and washing was also investigated.

Headspace solid phase microextraction for the gas chromatographic analysis of methyl-parathion in post-mortem human samples. Application in a suicide case by intravenous injection.

A simple and rapid procedure for the determination of methyl-parathion (m-p) in post-mortem biological samples was developed using headspace solid phase microextraction (SPME) and gas chromatography (GC) with nitrogen-phosphorous detection (NPD). Methyl-parathion was extracted on 85 microm polyacrylate SPME fiber. Salt addition, extraction temperature, and extraction time were optimized to enhance the sensitivity of the method. The linearity (y = 0.0473x - 0.0113, R2 = 0.9992) and the dynamic range (0.1-40 microg/ml) were found very satisfactory. The recoveries of methyl-parathion were found to be 46% in spiked human whole blood, 53% in spiked homogenized liver tissue, and 54% in spiked homogenized kidney tissue compared with samples prepared in water. The coefficients of variations for 2, 4, and 20 microg/ml of methyl-parathion in blood ranged from 0.9 to 5.1%, whereas the detection limit of the method was satisfactory (1 ng/ml in aqueous samples, 50 ng/ml in whole blood). The developed procedure was applied to post-mortem biological samples from a 21-year-old woman fatally poisoned (suicide) by intravenous injection of methyl-parathion. The intact insecticide was found in the post-mortem blood at a concentration of 24 microg/ml. No methyl-parathion was detected in the liver, kidneys, and gastric contents.

Amphetamine derivative related deaths in northern Greece.

Until 1997, only one amphetamine related derivatives (AMPs) fatality had been reported in Greece. Since then, amphetamine (AMP) or AMPs have been found in seven out of 1,500 post-mortem toxicological cases. The cause and manner of death of these seven cases were: 3,4-methylenedioxy-N-methamphetamine (MDMA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) poisoning (n = 1), drowning in water (n = 4), cranial injuries caused by a traffic accident (n = 1) and heart failure (n = 1). In the case where the use of AMP or AMPs was considered, the immediate cause of death post-mortem toxicological analysis revealed 2 microg/ml MDMA and 0.7 microg/ml MDEA in blood. MDMA was identified in two cases of drowning (2 microg/ml in blood in the first case and 1.7 microg/g in liver in the second case) and in the traffic accident case (0.4 microg/g in liver). Methamphetamine was detected in two cases of drowning (2.5 microg/ml in blood in the first case and 6 microg/g in liver in the second case). AMP was found in the heart failure case (0.2 microg/g in liver). Alcohol was present, together with AMP or AMPs, in four cases. These findings indicate an increase in the illegal abuse of AMPs in Greece. Because of this, we now routinely screen for AMPs.

Determination of opiates in postmortem bone and bone marrow.

Bone and bone marrow of a fatally poisoned heroin addict were analyzed by FPIA and GC-FID, immediately after death. A piece of the bone from the above case was buried for 1 year and analyzed by the same procedure. Morphine was detected in all specimens at concentrations of 195, 340 and 155 ng/g for bone marrow, bone and buried bone, respectively. A loss of 54.4% of morphine concentration was observed during 1-year burial. Such findings have potential forensic value in cases of skeletonized remains.

Death during deliberate propane inhalation.

Propane gas is used as a fuel and very rarely it is abused by young people in Greece. In this paper, we report a case of abuse of propane inhalation that resulted in accidental death. The determination of propane in autopsy samples was done by headspace gas chromatography and semiquantitation in liver, blood and the contents of the plastic bag through which the gas was diffused, which proved to be lethal.

Personal and environmental air sampling of methyl bromide during experimental greenhouse fumigation.

In this investigation methyl bromide, a widely used soil fumigant, was investigated with respect to workers exposure and environmental fortification at the greenhouses of Thessaloniki area, Northern Greece. By means of personal and environmental air sampling through charcoal, methyl bromide concentration was measured by gas chromatography using a capillary OV-1 column at 45 degrees C and flame ionization detector (FID). Personal air sampling for two workers showed that the levels of exposure to methyl bromide were 89 and 92 mg/m3 respectively. These values exceeded the safety limits. The mean maximum and mean minimum concentrations in the environmental air samples inside the greenhouse, for 8 hours duration, were 142 mg/m3 and 4 mg/m3, respectively. These concentrations were determined within four and eleven days after the application of methyl bromide.

Fatal animal poisonings in northern Greece: 1990-1995.

Fatal animal poisonings in northern Greece from 1990 to 1995 are recorded. A total of 926 specimens have been analyzed by chromatographic techniques. Pesticides caused 78% of the poisoning cases and all other toxic substances caused 22%. The animals affected were mainly cats, dogs, sheep, birds and bees.

Fatal human poisonings in northern Greece: 1990-1995.

Human mortality data due to toxic substances are presented for 1990 through 1995. The number of analyses required, results, sex of the deceased, toxic agents encountered and their fluctuations over the years are given. There was a decrease in pesticide poisonings with a corresponding increase in heroin deaths, but the total number of yearly poisonings did not vary significantly.