title: Optimization of dispersive micro solid-phase extraction for the rapid determination of benzophenone-type ultraviolet absorbers in aqueous samples.
abstract: A solvent-free method for the rapid analysis of six benzophenone-type UV absorbers in water samples is described. The method involves the use of dispersive micro solid-phase extraction (DmSPE) followed by the simultaneous silylation and thermal desorption (SSTD) gas chromatography-mass spectrometry (GC-MS) operating in the selected-ion-storage (SIS) mode. A Plackett-Burman design was used for screening and a central composite design (CCD) for optimizing the significant factors was applied. The optimal experimental conditions involved immersing 1.5mg of the Oasis HLB adsorbent in a 10mL portion of water sample. After vigorous shaking for 1min, the adsorbents were transferred to a micro-vial, and were dried at 122°C for 3.5min, after cooling, 2μL of the BSTFA silylating reagent was added. For SSTD, the injection-port temperature was held at 70°C for 2.5min for derivatization, and the temperature was then rapidly increased to 340°C to allow the thermal desorption of the TMS-derivatives into the GC for 5.7min. The limits of quantitation (LOQs) were determined to be 1.5-5.0ng/L. Precision, as indicated by relative standard deviations (RSDs), was equal or less than 11% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 87% and 95%. A preliminary analysis of the municipal wastewater treatment plant (MWTP) effluent and river water samples revealed that 2-hydroxy-4-methoxybenzophenone (BP-3) was the most common benzophenone-type UV absorber present. Using a standard addition method, the total concentrations of these compounds ranged from 5.1 to 74.8ng/L.
authors.affiliation: Department of Chemistry, National Central University, Chung-Li 320, Taiwan; Department of Chemical Engineering, Army Academy ROC, Chung-Li 320, Taiwan.
authors.forename: Wu-Hsun
authors.initials: WH
authors.lastname: Chung
authors.affiliation: Department of Chemical Engineering, Army Academy ROC, Chung-Li 320, Taiwan.
authors.forename: Shin-Hwa
authors.initials: SH
authors.lastname: Tzing
authors.affiliation: Department of Chemistry, National Central University, Chung-Li 320, Taiwan. Electronic address: wanghsiending@gmail.com.
authors.forename: Wang-Hsien
authors.initials: WH
authors.lastname: Ding
mesh_terms: D000327:Adsorption; D001577:Benzophenones / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D045483:Rivers / Q000737:chemistry; D052617:Solid Phase Microextraction / Q000379:methods*; D013473:Sunscreening Agents / Q000032:analysis*; D013696:Temperature; D014466:Ultraviolet Rays; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D001577:Benzophenones; D013473:Sunscreening Agents; D062065:Wastewater; D014874:Water Pollutants, Chemical; C005290:oxybenzone
keywords: Benzophenone-type UV absorbers; Dispersive micro solid-phase extraction; Thermal desorption–GC–MS; Water analysis