High-performance Liquid Chromatographic Determination of Urinary Trans, Trans-Muconic Acid Excreted by Workers Occupationally Exposed to Benzene

Key words: 
• Benzene /
• Trans /
• Trans-muconic acid /
• High-performance liquid chromatography

Abstract: To investigate the relationship between trans, trans-muconic acid (ttMA) as benzene metabolite of occupational workers and benzene concentration in air. Methods A rapid and sensitive high-performance liquid chromatography was developed to determine the level of urinary ttMA. ttMA was extrated from urinary samples in liquid-liquid phase a ODS (2) (5u) column (Φ4.6 mm× 150 mm) and detected at wavelength 264 nm in a UV detector using vanillic acid as an internal standard. The mobile phase was acetaticacid/tetrahydrofuran/methanol/water (v/v, 1:2:10:87). The method was validated with 56 urine samples collected from occupationally benzene-exposed individuals. Results A correlation coefficient (r = 0.9963 ) was found for ttMA ranging 0.10-10.00 μg/mL. The limit of detection was 0.10 μg/mL. The recovery and reproducibility were generally over 90%. There was a positive correlation between ttMA and benzene level in air. The equation was Y=0.859+0.108C (before work, r=-0.6200) or Y=1.980+0.179C (after work, r=0.7930). Conclusion This method can be used to determine and control the level of urinary ttMA in those who are occupationally exposed to benzene.