Determination of benzophenone-3 and metabolites in water and human urine by solid-phase microextraction and quadrupole ion trap GC-MS

In this paper, a novel technique has been developed for the determination of benzophenone-3 and its metabolites in urine using solid-phase microextraction (SPME) combined with gas chromatography-quadrupole ion trap mass spectrometry (GC-MS). Benzophenone-3 is a common ingredient found in sunscreens and other products. Because benzophenone-3 and other sunscreening compounds may be absorbed into the body, methods for monitoring the accumulation, metabolism, and excretion of these compounds need to be developed. Three kinds of SPME fibers were used and compared for this study. Parameters for the detection were examined in an aqueous medium and are listed as follows: equilibrium time, multiple extractions from the same vial vs. different vials, the maximum desorption temperature and time, and the effects of both salt and solvent on the extraction efficiency. Human urine samples were then spiked with standard benzophenone solutions and analyzed with the SPME method to determine linear range, limit of detection, and precision. Linear range determinations fell within 10-1000 ng/ml with precisions averaging 7% RSD. Ultimately a urine specimen taken after a human subject had applied a commercially available sunscreen product was tested for benzophenone and its metabolites. Benzophenone-3 and 2,4-dihydroxybenzophenone were detected and the former was subjected to both SPME and SPE quantitation methods with comparable results of 260 and 200 ng/ml, respectively. (C) 1998 Elsevier Science B.V. All rights reserved.