Determination of Pyrethroids and Phthalate Esters in Radix et Rhizoma Glycyrrhizae by Successive Ultrasonic-assisted Extraction and Dispersive Liquid-Liquid Microextraction Followed by Gas Chromatography-Mass Spectrometry
Abstract A rapid, inexpensive and efficient sample preparation method for simultaneous extraction and determination of three pyrethroids and seven phthalate esters in Radix et Rhizoma Glycyrrhizae samples was developed. The target analytes were extracted using a two-step extraction method including ultrasonic-assisted extraction and dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry (GC-MS). In ultrasonic-assisted extraction process, acetone was used as extraction solvent and extraction time was set as 3 min. In dispersive liquid-liquid microextraction process, optimized experimental conditions including 100 μL of CCl4 as extraction solvent and 1.0 mL of acetone as dispersant with 3% (m/V) of NaCl were adopted. The eluents were further quantitatively determined by GC-MS. All ten kinds of analytes were well separated, and the calibration curves showed good linearity, with correlation coefficients greater than 0.9992. Low detection limits of 0.0035 μg kg-1 for DMP to 1.0 μg kg-1 for IMIP were achieved. The method demonstrated good recoveries between the acceptable range of 79.7% for IMIP to 105.7% for TETR at three spiked levels with RSD