Simultaneous determination of urinary hyppuric and methylhyppuric acids through chromatographic methods: comparation between high performance liquid chromatography and capilary gas chromatography

Abstract

High performance liquid chromatography and capillary gas chromatography were compared for simultaneous measurement of hyppuric and methyl hyppuric acids in urine of workers co-exposed to toluene and xilene. Quantitative advantages offered by HPLC over capillary GC method are observed: better average recovery, wider dynamic interval in calibration curve and lower detection and quantification limits mainly when MHA measurement was performed. No significant difference was found between the values of HA higher than 1.0 g/g creatinine measured by the two chromatographic procedures. Regarding to MHA concentration the methods gave similar results and there was no significant difference between the values.