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Biomedical subjects

Tetsuya Ishiwata

Publications and source records attributed to Tetsuya Ishiwata.

7 recordsLinked to original sources

Absolute determination method using chirality for glufosinate and bialaphos by gamma-cyclodextrin modified capillary zone electrophoresis.

A novel absolute determination method using chirality without any calibration curves or comparison standards has been proposed for phosphorus-containing amino acid-type herbicides, glufosinate (D,L-GLUF) and bialaphos (BIAL). This method is based on a change in the enantiomeric ratio after the spiking of a known amount of the enantiomers with different enantiomeric ratios to a sample. D,L-GLUF was determined by adding a known amount of L-GLUF to the sample, derivatizing them with dansyl chloride, and measuring the ratio of the peak area of the D-isomer to that of the L-isomer by means of gamma-cyclodextrin modified capillary zone electrophoresis. The accuracy and precision of the method were evaluated using a synthetic sample. The mean values obtained for D- and L-GLUF agreed with the values taken within 1.6%; also the reproducibility was as good as less than 2.8%. The determination of BIAL was achieved by determining GLUF quantitatively produced by the acid hydrolysis of BIAL. The proposed methods were applied to the analysis of commercial herbicides and the validity and usefulness were evaluated.

Aminobutyrates↗

[Application of extraction needle using selective and enhanced polymer in the analysis of samples containing poisonous material].

Low concentrations of gas components usually need to be condensed before analyzing them by gas chromatography (GC). Extraction Needle using Selective and Enhanced Polymer (EN-SEP) is a recently developed devise for condensing the components that are difficult to detect by using GC. EN-SEP consists of a needle which contains methacrylate co-polymer. Gas components are adsorbed and condensed on the polymer by passing through the needle. This paper describes the usefulness of EN-SEP in a criminal case. EN-SEP was successfully applied to condense and detect a trace of propylene glycol monomethyl ether contained in a soft drink by using gas chromatography/mass spectrometry.

Beverages↗

[Development of salicylic acid dipstick test].

A dipstick test was successfully devised for the screening of salicylic acid in urine. It, named "salicylic acid dipstick test", is TLC plastic sheet which was soaked into 5% (w/v) of ferric chloride aqueous solution, then was covered with Oblate and dried. The test paper was dipped into the sample, then it immediately turned purple under the condition of more than 100 microg/ml of salicylic acid in urine. This device was useful for the emergency screening of salicylic acid in acute poisoning cases with aspirin.

Adult↗

Analysis of toluene in exhaled air of glue sniffers and workers using thinner at work place.

Toluene concentrations in exhaled air of workers using thinner at work place and glue sniffers were measured by gas chromatography (GC). Toluene concentrations in exhaled air of workers were significantly lower than those of glue sniffers. This suggests that a worker does not inhale as much thinner as a sniffer and that the analysis of thinner in exhaled air can be an indicator for its inhalation. It is also considered that the analysis of toluene concentration in the exhaled air gives an important clue whether the person inhaled thinner during working or self-abuse.

Adolescent↗

[Development of salicylic acid detector tube].

A detector tube was successfully devised for the screening of salicylic acid in urine. It, named "salicylic acid detector tube", consists of glass tube in which silica gel coated with 5% (w/w) of ferric chloride is enclosed. A pipette rubber cap was attached to an end of the tube, and another end was inserted into urine sample. The sample was then introduced into the tube, the color of the reagent immediately turned purple under the condition of more than 50 microg/ml of salicylic acid in urine. This device was useful for the emergency screening of salicylic acid in acute poisoning cases with aspirin.

Acute Disease↗

[A case of chloropicrin detection by purge and trap gas chromatography/mass spectrometry].

Chloropicrin (CP) is an agricultural chemical used as insecticide or fungicide, which occasionally causes accidental poisoning and may used in criminal cases including suicide and homicide. Although CP is usually analyzed using gas chromatography/electron capture detection technique (GC/ECD), further identification by gas chromatography/mass spectrometry (GC/MS) may be required from the view point of forensic chemistry and also clinical toxicology. However, it is very difficult to detect a trace of CP by routine GC/MS. The present paper describes a criminal case, in which GC/MS equipped with curie point purge and trap sampler was successfully applied to detect a small amount of CP.

Crime↗