A Standard Method For Determination Of Acetone In Urine As A Biomarker For Occupational Exposure To Acetone

ObjectiveAcetone is a solvent widely used in the laboratory and industry. In order to protect workersexposed to acetone, it is of great significance to carry on environmental monitoring andbiological monitoring for it. Concentrations of acetone in urine, alveolar air, and blood wereappropriate biological index of exposure to acetone. Many reports suggested that urinary acetoneconcentration is the best biological index of occupational exposure to acetone because thecorrelation between the environmental exposure concentration and the concentration in urine ofacetone was strongest. The BEIs recommended by the ACGIH and BATs recommended by theDFG were50mg/l and80mg/l respectively for acetone in urine. The purpose of the present studywas to set a standard method for determination of acetone in urine and provide supports in thetechnology and method for the next research of bio-exposure limits of urinary acetone.MethodTo minimize the basement interference and increase the detection limits of the method,head-space technique and gas chromatograph method with FID detector was adopted to extractand separate acetone from the urine for qualitative and quantitative analysis. According todemands of Guide for Establishing Occupational Health Standards, on the one hand the bestdetermination conditions of head-space and GC were tested and chosen, and on the other handthe performance of each index was assessed and discussed for this established method.ResultsAs pretreatment,3.0ml of urine and4.0g of sodium sulfate were put into a head-space vialof20ml which was sealed by septum, and then were heated for20min in warm bath of50degreecelsius. It can obtain the highest detection limits by this pretreatment. The regression equationsof standard curves of the method was satisfactory with Y＝3196.3X+4753（r=0.9995）in theconcentration range from4.9mg/L to157.6mg/L for acetone. The lowest detectableconcentration was0.67mg/L for urinary acetone. The results showed that recovery percentagesat three levels of concentration were93.92%,104.46%and101.20%, respectively. The precisionfor inter-and intra-day, expressed as relative standard deviation (RSD), were all less than10%. It has been confirmed that the determination of acetone by this head-space gas chromatograph wasnot interfered by volatile compounds such as methanol, methylene chloride and methyl ethylketone (MEK) in the workplace together with acetone. Stability test found that urine sampleswere stable for at least7days when stored at4℃.ConclusionThe head-space gas chromatography method proposed in this study was simple and easy touse with good accuracy and less interference for determination of acetone. These results suggestthat the method could be used as a standard method for biological monitoring of acetone. Theprecision of the method can be improved if autormatic sampler was used.