Simultaneous determination of benzene, toluene, ethylbenzene, and xylenes in urine by thermal desorption–gas chromatography

Comparison Between Dynamic Headspace and Headspace Solid-Phase Microextraction for Gas Chromatography of Btex in Urine

“…Smokers had significantly higher urinary BTEX concentrations than non-smokers. Our results were similar to those reported by others (5,7,10,13). The exception in our study was toluene, Our results were, however, higher than those reported in our previous study (17), probably due to a difference in sampling time; in this study we collected samples in the winter, and in the earlier study in the summer when lower concentrations of BTEX in air (affecting BTEX concentration in urine) were found because of reduced heating and enhanced photochemical degradation during the summer.…”

“…Accuracy for both methods was similar and greater than those previously reported (10,11,16). Relative standard deviations at the two BTEX concentrations were also similar: RSD≤11 % and ≤10 % for HS-SPME-GC-MS and PT-GC-PID, respectively.…”

“…Since it is not known for BTEX to occur in human urine as a result of normal physiological metabolism, the finding of measurable concentrations of BTEX in the urine should reflect exposure to these aromatic compounds. At the level of environmental exposure, the concentration of BTEX excreted unmodified in the urine is low; the proportion is usually in the order of 1 % or less of the absorbed dose (9), so the quantification of BTEX in the urine of general population has become possible thanks to the development of the very sensitive analytical techniques which permit determination at levels as low as ng L -1 (1,5,10). Several instrumental variations are described for the low level BTEX determinations in the urine.…”

“…Several instrumental variations are described for the low level BTEX determinations in the urine. These include different sampling techniques such as dynamic headspace (thermal desorption, TD and purge and trap, PT) (10-12) and headspace solid-phase microextraction (HS-SPME) (1, 5, 13) followed by gas chromatographic separation and flame ionization (10)(11)(12) and/or mass spectrometric (1,5,10,13) detection.…”

Determination of benzene, toluene, ethylbenzene, and xylenes in urine by purge and trap gas chromatography

“…Recently, with the development of new analytical techniques with higher sensitivity it is possible to measure BTEX in urine [5 -7]. The analytical approach in BTEX analysis has been either dynamic headspace [5] or headspace solid-phase microextraction (HS-SPME) [6,7] followed by gas chromatographic separation and flame ionization [5] and/or mass spectrometry detection [5 -7]. Headspace sampling is an indirect method for determination of volatile analytes from a liquid or solid sample in which the vapour phase is analysed.…”