Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop Combined with High Performance Liquid Chromatography for Analysis of 15 Phthalates in Water

Background: Consistent toxicological evidence indicate that phthalates can cause adverse effects on human health. The concern over phthalate pollution and exposure has been emphasized in recent years. Therefore, the sensitive, reliable, and rapid detection of phthalates in water is of great importance. Objective: In this study, dispersive liquid liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) combined with HPLC-UV detection was established and applied in the preconcentration and detection of 15 phthalates in drinking and river water samples. Methods: A mixture of acetonitrile (dispersant) and 1-dodecanol (extractant) was injected into water samples, which had been added with sodium chloride. The cloudy solution was formed by hand-shaking. After centrifugation, the sample solution was cooled in a refrigerator, and the solidified organic droplet was collected. It melted at room temperature and was injected into the HPLC system for analysis. The quantification was based on the working curves. Results: Under optimum conditions, this method showed good linearity in the range of 0.1-100 or 0.5-100 mu g/L with correlation coefficients greater than 0.999. The method had the LODs ranging from 0.013 to 0.16 mu g/L with the enrichment factors of 102-218. The recoveries of the method ranged from 86.8 to 119% with RSDs less than 12.6%. The interday and intraday RSDs were 6.35-13.5% and 3.00-13.7%, respectively. The established method has been successfully applied to the analysis of phthalates in drinking and river waters. Conclusions: The established method is rapid, sensitive, cost-effective, and environmentally friendly. It can be applied to the analysis of 15 phthalates in drinking and river water samples. Highlights: A method of DLLME-SFO combined with HPLC-UV detection has been established for the analysis of 15 phthalates in drinking and river water samples. The established method was rapid, sensitive, accurate, cost-effective, and environmentally friendly. The established method was successfully applied to the analysis of 15 phthalates in bottled, tap, and river water samples.