Determinations of Bisphenol A in Household Dusts by Solid-Phase Microextraction with Microwave Assisted Extraction

摘要

Indoor dust has been known as a sink for many semi-volatile organic compounds, such as bisphenol A (BPA). Since indoor environment can protect dust from sunlight, rain and biological degradation, pollutants then could be persistent and accumulated in the residential environment. Up to now, the analysis of BPA in dust is solvent and time consuming. Therefore, a method for the measurement of BPA in dusts simultaneously by using microwave assisted direct-immersion solid-phase microextraction (MAE-DI-SPME) has been developed to determine the distributions in Taiwan. In this study, commercial vacuum cleaner was used to collect household dusts while particles with diameter smaller than 150μm were filtered out by stainless mesh. Afterwards, 0.02g dust sample was spiked with 2.5 μg/g of surrogate (bisphenol A d-16) in a 4mL vial and stood for overnight. RO water of 2.5mL was added into the sample the next day, followed by the filtration and MAE-DI-SPME extraction procedures. Gas chromatograph and mass spectrometer (GC/MS) was employed for the analysis. Several parameters affecting the SPME extraction efficiency were optimized. The results showed that the desorption efficiency was 100% when the desorption time was 20 min under 250°C. The best suitable fiber coating was 65μm Polyethylene Glycol (PEG) and the optimum condition of MAE-DI-SPME for extraction of BPA in dust was 20 minutes at 80°C. The linear range for the analysis was 1.25 ～ 1250 ng/g dust (r=0.99). For indoor dust samples in Taiwan, the median, mean and rage of BPA concentrations were 4.98, 11.06 and 1.54～39.99 μg/g, respectively. Relatively to headspace extraction, the established method of MAE-DI-SPME for the determination of bisphenol A in indoor dust provides good linearity and precisions. Besides, compared with traditional extraction methods, the MAE-DI-SPME provides a time saving, easy for operation and solvent-free procedure.