[Applications of the Fe(3)O(4) nanocomposite modified by Humic Acid in determination of S-phenylmercapturic acid in urine by dispersive solid-phase extraction and HPLC].

Objective: To establish a method for determination the S - phenylmercapturic acid in urine by dispersive solid - phase extraction using Humic Acid/Fe(3)O(4) magnetic nanocomposite as adsorbent. Methods: The 5 ml of urine samples were adjusted to pH 1.0 and extracted by Fe3O4@HA. Then the analytes were separated on EC-C(18) capillary column and detected by HPLC-VWD. The S-phenylmercapturic acid was characterized by the retention time and quantified by peak area and external standard method. Results: The standard curves of SPMA showed significant linearity between 0.04~1.00 mg/L ( r =0.999 7) . The average recovery was 94.2%~102.4%. The intra-day and inter-day precisions ( RSD ) were 2.9~6.7% ( n =6) and 3.1~7.5% ( n =6) respectively. The detect limit of SPMA was 0.012 g/L (S/N=3) . Conclusion: This method is simple, rapid, sensitive and accurate. It is applicable for determination of SPMA in the urine of works who were exposed to benzene.