Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1169870 | Analytica Chimica Acta | 2008 | 6 Pages |
Abstract
No previous publications about percutaneous absorption of polyethylene glycol 25 p-aminobenzoic acid (PEG-25 PABA) have been found in the literature and the expected levels to be found in human urine after sunscreens use are unknown. The method proposed here is suitable to determine PEG-25 PABA in the urine of sunscreens users in order to carry out studies on body accumulation/excretion. It is based on solid-phase extraction (SPE) with size-exclusion liquid chromatography determination. Solid-phase extraction allows the analyte to be retained and subsequently eluted for a clean-up, using a silica-based cartridge. The size-exclusion liquid chromatography of the eluted allows the rest of matrix interferences to be avoided. Fluorescence intensity was measured at λem = 350 nm (λexc = 300 nm). The sensitivity of the proposed method is in the order of 450 ± 5 mL ngâ1 and the detection limit (3 Sy/x/b) in the measured solutions is in the order of 13 ng mLâ1, that is 2.6 ng mLâ1 in urine samples. The method enables PEG-25 PABA to be determined in both, spiked and unspiked human urine samples. Results obtained for spiked human urine samples (11-100 ng mLâ1) demonstrated the accuracy of the method. The mean relative standard deviation of the results was in the order of 3-10%. Three volunteers applied a sunscreen lotion containing a 8% PEG-25 PABA sunscreen cream and their urinary excretion was controlled from the moment of application until the excreted amounts were no longer detectable.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
A. Balaguer, A. Chisvert, A. Salvador, M. Herraez, O. Diez,