Stir-bar-sorptive extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry for simultaneous analysis of UV filters and antimicrobial agents in water samples
Stir-bar-sorptive extraction (SBSE) with liquid desorption (LD) and ultra-high-performance liquid chromatography-electrospray ionization triple-quadrupole tandem mass spectrometry (UHPLC-(ESI)MS-MS) were used for analysis of six personal care products in environmental water: four UV filters (2,2-dihydroxy-4-methoxybenzophenone, benzophenone-3, octocrylene, and octyldimethyl-p-aminobenzoic acid) and two antimicrobial agents (triclocarban and triclosan). Experimental conditions that affect SBSE-LD sorption efficiency (extraction time and temperature, sample pH, and ionic strength) and desorption efficiency (solvent, temperature, and time) were optimized. The method proved to be sensitive-a 50-mL sample was used to determine these compounds in environmental waters at trace levels. The detection limits of the analytical method were 2.5 ng L-1 for river water and 5-10 ng L-1 for effluent and influent sewage water. In river waters, benzophenone-3 was found at levels from 6 ng L-1 to 28 ng L-1 and triclosan at levels < LOQ. Benzophenone-3 was found between 75 and 127 ng L-1 in influent sewage, whereas concentrations of benzophenone-3 and triclosan were commonly below 25 ng L-1 in effluent sewage.