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 determinat ion of benzophenone-3 and its metabolites in urine using solid-phase m icroextraction (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 oth er sunscreening compounds may be absorbed into the body, methods for m onitoring the accumulation, metabolism, and excretion of these compoun ds need to be developed. Three kinds of SPME fibers were used and comp ared for this study. Parameters for the detection were examined in an aqueous medium and are listed as follows: equilibrium time, multiple e xtractions from the same vial vs. different vials, the maximum desorpt ion temperature and time, and the effects of both salt and solvent on the extraction efficiency. Human urine samples were then spiked with s tandard benzophenone solutions and analyzed with the SPME method to de termine 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 appli ed a commercially available sunscreen product was tested for benzophen one and its metabolites. Benzophenone-3 and 2,4-dihydroxybenzophenone were detected and the former was subjected to both SPME and SPE quanti tation methods with comparable results of 260 and 200 ng/ml, respectiv ely. (C) 1998 Elsevier Science B.V. All rights reserved.