Determination of Metal Ions in Pinellia ternata by High Performance Liquid Chromatography-Ultraviolet Detector

Abstract

In this study, trace amounts of heavy metal ions copper, lead, mercury and cobalt in Pinellia ternata samples were detected by ionic liquid ultrasonic assisted dispersion liquid–liquid microextraction, combined with high performance liquid chromatography-ultraviolet detector. The method used sodium diethyldithiocarbamate as complexing agent and phosphoric acid ionic liquid Trihexyl(tetradecyl) phosphine bis[(2,4,4-trimethyl)] amyl phosphonate (cyclophosphate IL104) as extractant. Methanol: 0.2% phosphoric acid (60:40) was used as mobile phase for separation and UV detector was used for detection, the flow rate was 1 mL/min and the injection volume was 10 μL. In this paper, the effects of sample pH, complexing agent concentration, ultrasonic time, centrifugation time and speed and ionic strength were optimized. Under the optimal conditions (50 μL ionic liquid cyclic phosphine IL104, pH = 5, 0.5% sodium diethyldithiocarbamate, ultrasonic time of 30 min, centrifugation speed of 4000 r/min, 0.1 g NaCl), the recovery of spiked standard was 89.0~98.2%. High performance liquid chromatography had the characteristics of low detection limit, accurate and reliable determination results, high sensitivity, strong specificity and good reproducibility.