| dc.description.abstract | Alkyl p-hydroxybenzoates, also called parabens, have been widely added to cosmetics, foods, and pharmaceuticals as preservatives in the 20th century due to their low prices, lack of odor and color, and resistances to hardening. According to recent studies, parabens might interfere with the endocrine system and the human reproductive system, and have been classified as a potential endocrine disrupter. People can be exposed to parabens from indoor dusts, since dusts are the final depositional sites of most environmental pollutants. Given the potential danger of parabens, it is necessary to develop a method to analyze parabens in indoor dust.
This study developed a fast, efficient, one step clean-up and eco-friendly analysis method to determine the concentration of parabens in indoor dust. The method involves a newly developed pretreatment method, dual-vortex assisted matrix solid-phase dispersion (DVA-MSPD) coupled with isotope dilution-UHPLC-QTOF-MS detection.
The parameters of DVA-MSPD were optimized by Box-Behnken design and analysis of variance (ANOVA). The optimal conditions of DVA-MSPD were: weighting 0.1 g indoor dust, 0.1 g sodium sulfate anhydrate, and 0.1 g C18 into a centrifuge tube, homogeneously blended by vortex for 1 minute, add 5 mL of extractant (ACN : MeOH = 1:1 v/v), and extract by vortex for 30 seconds. After vortex, the blend was centrifuged at 3000 rpm for 10 minutes, then the supernatant was collected and dried under nitrogen, and reconstituted with methanol to 100 µL. For analysis, a fraction of the 3 µL solution was injected into the UHPLC-QTOF-MS system for quantitation.
The detection limit were 0.9 - 2.8 ng/g. Intra-day and inter-day precisions (% RSD) for nine analytes were less than 8%. In indoor dust samples, methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate and propyl 4-hydroxybenzoate were detected in most samples, the concentration of these three parabens were ranged from 13.3 to 339.6 ng/g. butyl 4-hydroxybenzoate was detected in few sample, and isopropyl 4-hydroxybenzoate, isobutyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, pentyl 4-hydroxybenzoate, hexyl 4-hydroxybenzoate were not detected in all the samples. | en_US |