DETERMINATION OF TRICLOSAN IN HUMAN DENTAL PLAQUE BY GAS-CHROMATOGRAPHY WITH ATOMIC-EMISSION DETECTION

A validated gas chromatographic method for the determination of triclo san in human dental plaque is described, Based on plaque sample weight s of 10 mg, the limit of detection (2 x S/N) is 0.5 mu g/g, The method is linear (r = 0.9986) from the limit of detection to 50 mu g/g. Reco veries from placebos spiked with 2.0, 25, and 50 mu g/g of triclosan w ere 105.6% +/- 7.5%, 107.2% +/- 3.1%, and 99.1% +/- 1.1%, respectively (n = 3 at each level), Twenty replicate preparations and analyses of a homogenized sample, conducted by two operators over the course of 4 days, showed agreement to within 9% RSD, Analyses of dental plaque col lected from patients after brushing with dental cream containing tricl osan, shows triclosan to be retained in dental plaque at concentration s above the minimum inhibitory concentration (1 mu g/g) after 12 h.