K. Kimura

Sulfide concentrations in postmortem mammalian tissues.

Postmortem changes in sulfide concentrations in body tissues were examined in autopsied rats exposed to hydrogen sulfide concentrations of 550 to 650 ppm, and in nonexposed rats and humans. Analyses were made by gas chromatography, following an extractive alkylation. Sulfide concentrations in the blood, liver, and kidneys of rats increased in both the exposed and nonexposed groups, depending on the lapse of time after death. On the other hand, the lung, brain, and muscle showed little or no change in sulfide concentration with elapse of time after death. The data obtained from human tissues were almost the same as those for rats, except data for blood, in which no or little increase of sulfide was observed.

Methamphetamine and amphetamine concentrations in postmortem rabbit tissues

The feasibility of detecting methamphetamine and its major metabolite, amphetamine, in postmortem tissues over a 2-year period was examined. It is important to determine if the abuse and toxic effects of drugs can be proved from evidence found in decayed, submerged, or stained tissue materials. The blood, urine, liver, skeletal muscle, skin and extremity bones from rabbits given methamphetamine intravenously were kept at room temperature, under 4 different conditions: sealed in a test tube, dried in the open air, submerged in tap water and stained on gauze. Methamphetamine was present in all the samples, with slight change in concentration in case of sealed and air dried tissues. Changes varied in bones kept in water. There were considerable decreases in methamphetamine in blood and urine stains. Despite long term storage, drug abuse and/or toxicity could be determined, in all tissues examined.

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.

Simultaneous determination of paraquat and diquat in human tissues by high-performance liquid chromatography

A simple, sensitive, reliable, and economical method for simultaneous determination of paraquat dichloride and diquat dibromide in human biological materials has been developed, using high-performance liquid chromatography. The drugs were extracted from the sample with a Sep-Pak C18 cartridge and applied to a chromatograph with the internal standard, L-tyrosine. Paraquat and diquat were clearly separated on the octadecylsilica column with a mobile phase of 0.5% potassium bromide in 5% methanol solution, containing triethylamine (1 ml/l). The pH of the mobile phase was adjusted to 3-4 with 1.3 M phosphoric acid. Two ultraviolet wavelengths were selected, 256 nm for paraquat as well as the internal standard, and 310 nm for diquat. The calibration curves were linear in the concentration range 0.1-10 micrograms/g, and the lower limit of detection was 0.05 microgram/g. We used this method to examine the concentrations of paraquat and diquat in tissues of an individual at autopsy.

Gasoline and Kerosene Components in Blood - A Forensic Analysis

A reliable method to analyse small amounts of fuel components in biological materials, using two simultaneous procedures, head space and solvent extraction methods has been developed. Gas chromatography/mass spectrometry (GC/MS) was used for qualitative and quantitative determinations. The aliphatic hydrocarbons with carbon numbers of 5 to 8 and aromatics such as benzene, toluene and xylenes were detected in laboratory animals, following exposure to gasoline vapour, using the head space method. Aliphatic hydrocarbons with carbon numbers over 9 as well as the aromatics with carbon number 9 group including cumene, mesitylene, pseudocumene and 1,2,3-trimethylbenzene were determined by the solvent extraction method following exposure to kerosene vapour. The lower limits of detection were 0.01 μg and 50 pg in gasoline and kerosene components, respectively. The methods were found to be applicable in confirming the cause of human deaths.

Sensitive determination of diazepam and N-desmethyldiazepam in human material using capillary gas chromatography-mass spectrometry

A reliable and sensitive capillary gas chromatographic-mass spectrometric method was developed for the detection and determination of diazepam and its major metabolite, N-desmethyldiazepam, in human material. Medazepam served as the internal standard. Quantitative determination was achieved using mass fragmentography with selected ions of m/z 256 for diazepam and m/z 242 for N-desmethyldiazepam and medazepam. The limit of detection was 1 ng/g and the recoveries were 98.54 +/- 3.95% for diazepam and 98.66 +/- 6.48% for N-desmethyldiazepam. The calibration graph was linear over the concentration range from 1.0 ng/g to 1.0 microgram/g for diazepam and N-desmethyldiazepam. Using this method, trace amounts of diazepam and N-desmethyldiazepam were detected in the tissues of an autopsied individual.

Components of paint thinner in body fluids clearly detected using the salting-out technique

For a more sensitive detection of paint thinner components in body fluids, we made use of a salting-out technique, with sodium chloride added to blood samples followed by gas chromatography, using the headspace method. The detection of ethyl acetate and isobutanol was considerably enhanced using these approaches.

Toxicological analysis of thiamylal in biological materials by gas chromatography/mass spectrometry

A reliable and sensitive method to analyze thiamylal in biological materials was developed, using gas chromatography/mass spectrometry (GC/MS). A quantitative determination was made by use of mass fragmentography with the lower detection limit of 0.01 microgram/g. Thiopental was used as the internal standard. Distribution of the drug in the blood and body tissues of rats was examined. The method was then used to detect thiamylal in tissues from an autopsied patient and concentration of this drug in the body materials was evaluated, from medico-legal aspects.

Toxicological analysis of lidocaine in biological materials by using HPLC.

A rapid and reliable method to analyze lidocaine in biological materials was developed using column extraction method and high performance liquid chromatography (HPLC). Two peaks for lidocaine and procaine as an internal standard (IS) were separated clearly with no interfering peaks appearing in the chromatogram. The annual change of lidocaine caused intoxications was described. From medico-legal aspects, the method was applied to authentic samples from autopsied victims and concentrations of lidocaine in 29 cases were evaluated briefly.

Screening of volatile compounds present in human blood using retention indices in gas chromatography

The retention index in gas chromatography was introduced to screen volatile compounds in blood. Sixty-one organic compounds with high volatility were determined using a gas chromatograph with a flame ionization detector and a packed column system with 10% OV-17. Porapak P was used as a supplementary column for determining alcohol. Detection limits were determined for several substances. This method was used to analyse blood samples obtained at autopsy from patients suspected of solvent abuse. This approach proved to be superior to conventional gas chromatography in that mixed unknown volatiles in the blood could be identified simply and rapidly.