Azo-linked porous organic polymers/polydimethylsiloxane coated stir bar for extraction of benzotriazole ultraviolet absorbers from environmental water and soil samples followed by high performance liquid chromatography-diode array detection.

With 4,4'-diaminoterphenyl and phloroglucinol as the monomers, Azo-linked porous organic polymer (PP) was prepared by a green mild azo reaction. Azo-PP is rich in phenolic hydroxyl groups and benzene rings, which can form intermolecular hydrogen bonds with the phenolic hydroxyl groups in interest benzotriazoles (BZTs). The π-π interaction between the benzene ring and the triazole ring would promote the adsorption of target BZTs on Azo-PP. Azo-PP/polydimethylsiloxane (PDMS) coated stir bar was prepared via sol-gel technique for the extraction of target BZTs. Compared with commercial stir bar, Azo-PP coated stir bar showed superior extraction efficiency (75-88% vs 45-65%) under similar conditions and kinetics (50 min vs 120 or 360 min). A method of stir bar sorptive extraction (SBSE) combined with high performance liquid chromatography (HPLC)-diode array detector (DAD) was developed to analyze six target BZT UltraViolet (UV) absorbers. The optimization of SBSE conditions for extraction of interest BZTs was performed by single-factor test. Under the optimized conditions, the limits of detection within 0.12-0.33 μg/L were achieved for six BZT UV absorbers, with the linear range within 0.5-100 μg/L. The method was applied to detect six BZT UV absorbers in the East Lake water, Yangtze River water, and campus soil samples. No BZT was detected in any of the samples. The recoveries of target BZTs in spiked samples were found in the range of 94.9-118%, 96.2-118%, and 88.2-119%.