Determination Of Triclosan Research Articles

Voltammetric Detector for Liquid Chromatography: Determination of Triclosan in Rabbit Urine and Serum

A flow-electrolytic cell containing a strand of carbon fibers has been designed and characterized for use in a voltammetric detector for high-performance liquid chromatography. The detector was used for determination of triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether) in rabbit serum and urine. Analysis of rabbit serum and urine 1 day and 1 to 5 days, respectively, after ingestion of oral triclosan revealed that the concentration of triclosan was higher than for control serum and urine. The concentration reached maximum levels after 6 h and 34 h or 44 h in serum and urine, respectively. When triclosan was determined in rabbit samples with the method proposed the results obtained were comparable with those obtained by high-performance liquid chromatography with ultraviolet detection.

Electrochemical determination of triclosan at a mercury electrode

A voltammetric method for the determination of trace amounts of triclosan was developed. Differential pulse voltammetry of triclosan exhibits tensammetric peak at the adsorption and desorption potential of triclosan. In the potential range where adsorption occurs, the base current is depressed. The determination method is based on the adsorption of triclosan on hanging mercury drop electrode and desorption of triclosan at negative tensammetric peak. The system showed no positive tensammetric peak on hanging mercury drop electrode under the experimental conditions. The tensammetric peak potential of triclosan was between −1190 and −990 mV (versus Ag/AgCl), depending on pH, scan rate, accumulation potential, accumulation time and presence of organic materials. Variation of the scan rate between 80 and 500 mV s −1 caused a linear increase in the tensammetric peak height. The peak current was proportional to the concentration of triclosan over the range 2.5–60 μg l −1. Under optimum experimental conditions (pH=7, accumulation potential of −450 mV and accumulation time of 90 s), the detection limit (DL) was obtained as 1.9 μg l −1 and the relative standard deviation (R.S.D.) was lower than 3%. The method was applied to the determination of triclosan in samples of toothpaste (containing 0.3% triclosan) and wastewater.

Determination of triclosan in personal health care products by liquid chromatography (HPLC)

An isocratic reversed-phase liquid chromatographic (HPLC) method is proposed for the practical and reliable determination of triclosan, an antimicrobic agent incorporated into a variety of personal heath care products. Chromatographic separations were performed on a C-18 column using acetonitrile–TEA phosphate (70 mM; pH 3.5) 55:45 (v/v) as mobile phase and UV detection at 230 and 280 nm. The selectivity of the method was assured by the on-line photodiode array detector. The identity of the triclosan peak was also confirmed by HPLC MS. The method was successfully applied to the determination of triclosan in commercially available health care products (deodorant stick, dentifrice gel, mouthrinse, toothpaste and handwash). All the products displayed triclosan concentrations in compliance with the EEC directive (≤0.3%).

Determination of triclosan in human dental plaque by gas chromatography with atomic emission detection

AbstractA validated gas chromatographic method for the determination of triclosan in human dental plaque is described. Based on plaque sample weights of 10 mg, the limit of detection (2 × S/N) is 0.5 μg/g. The method is linear (r = 0.9986) from the limit of detection to 50 μg/g. Recoveries from placebos spiked with 2.0, 25, and 50 μg/g of triclosan were 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 collected from patients after brushing with dental cream containing triclosan, shows triclosan to be retained in dental plaque at concentrations above the minimum inhibitory concentration (1 μg/g) after 12 h.

Determination of free and conjugated triclosan-1 in blood by electron capture gas liquid chromatography-2.

Unconjugated triclosan in blood can be determined by extraction with hexane, followed by its conversion to an acetyl derivative and analysis by electron capture gas liquid chromatography. The conjugated triclosan can be analyzed by an identical procedure, after the complexes have been hydrolyzed with hydrochloric acid. The method was validated by recovery studies using spiking and radioactive techniques and can be used for the determination of triclosan in blood in the concentration range of 1 ppb (ng/ml) to 100 ppm (µg/ml). The precision and accuracy of the method are discussed, and examples of its application are presented.