Rapid Determination of Aristolochic Acids in Environmental Water Using Ultrasonic-assisted Dispersive Liquid-Liquid Microextraction Coupled with High Performance Liquid Chromatography

A novel method was developed for analysis of aristolochic acid I and II (AA-I and AA-II) in environmental water by ultrasonic-assisted dispersive liquid-liquid microextraction (US-DLLME) coupled with high performance liquid chromatography (HPLC). The effects of kinds of the extraction solvent and the disperser solvent, the volumes of the extraction solvent and the disperser solvent, the ultrasonic time, the pH value and salt addition in the feed solution on enrichment factor were investigated. Under the optimal extraction conditions, the enrichment factors of up to 95.9 for AA-I and 93.4 for AA-II were obtained. The established method showed good linearity for both AA-I and AA-II in the concentration range from 0.01 to 2.00 mu g/mL with correlation coefficients (R2) of 0.9994 and 0.9997, respectively. The limits of detection (LODs) were 2.5 and 3.0 ng/mL, and the limits of quantitation (LOQs) were 8.0 and 9.5 ng/mL for AA-I and AA-II , respectively. The pretreatment procedure was completed within 12 min. The recoveries of AA-I and AA-II in spiked samples were from 91.7% to 96.9% with relative standard deviations (RSDs) less than 5.7% for Liuyang River samples. The recoveries of AA-I and AA-II in spiked samples were from 91.9% to 97.8% with RSDs less than 5.1% for Xiangjiang River samples. The results demonstrated that the proposed method was sensitive, fast and environmental-friendly, and could be suitable for analysis of AA-I and AA-II in environmental water.