Acta Biomedica Scientifica (Feb 2013)
Gas chromatographic determination of thiodiglycolic acid contentS in urine of polyvinyl chloride production workers
Abstract
The method, of determination of the thiodiglycolic acid. (TDGA) in urine using gas-liquid chromatography on the capillary column HP-5 with the flame ionization detection was developed and. certified. Optimal conditions for chromatography were chosen: the conditions for preparing the samples with use of chemical derivatization by methanol followed by the liquid. — liquid microextraction were optimized; the metrological studies were performed. We used gas chromatograph AGILENT 7890A with flame-ionization detector (FID) equipped with autosampler AGILENT 7693 which allows to regulate the depth of chromatographis springe needle immersion into the vial. The control of the chromatograph and. the autosampler functions as well as the collection, and. processing of the chromatograms are realized by the software programme GC ChemStation. Following reagents and. materials were used to prepare the samples and. model solutions: thiodiglycolic acid. (TDGA) (98 % Aldrich), dimethyl ether of TDGA, ethyl acetate (extra pure), methanol (e.p.), sulfuric acid (chemically pure), natrium sulfate (chemically pure), distilled water, urine samples free of TDGA. Preparation of the sample includes derivatization with methanol in the presence of sulfuric acid, as well as the liquid-liquid, microextraction of the TDGA dimethyl ether with ethyl acetate and. centrifuging. The identification, of TDGA dimethyl ether on the chromatogram, was realized with use of absolute time of retaining that was controlled by the comparison, and. imposing of received chromatograms with two chromatograms of model TDGA mixtures in the urine of different concentrations as well as with the chromatogram of model mixture of TDGA dimethyl ether in ethyl acetate. The calibration curve was received with use of five model TDGA solutions in water. The range of the concentrations determined, in the urine was 0,4-90 μg/cm3 the interalaboratory precision S was 0,065 and. the accuracy (P = 0.95) was 15 %. The thiodiglycolic acid contents was studied in the employees of the main departments of the polyvinyl chloride production. It was found that content of this metabolite may depend on the duration and the dose of exposure. The highest concentrations of TDGA in the urine are typical for the departments of production of vinyl chloride from 1,2-dichloroethane.
