Simultaneous Determination of Thiocyanate and Perchlorate in Vegetables by Ultrasonic Assisted Extraction of Hot Water-Ion Chromatography

A method was developed to determine thiocyanate and perchlorate in vegetables. The sample was extracted by ultrasonic assisted with ultrapure water and filtered after centrifugation as pre-treatment technology.Then the samples were separated with an IonPac AS16 anion analysis column by gradient elution with KOH solution,detected by conductivity detector,and quantified by external standard method. The results showed that,the calibration curve of thiocyanate and perchlorate was linear in the range of 0.2~5.0 mg/L and 0.04~1.00 mg/L with correlation coefficients of 0.9997 and 0.9989,respectively. The limits of quantitation were 0.005,0.008 mg/L,respectively. The recoveries were in the range of 89.9%~98.4% and 81.2%~94.4%,and relative standard deviations repeatability test were 1.6% and 6.9%,respectively. In the result, vegetable samples all contained a certain amount of thiocyanate and perchlorate,and the highest content of carrots dry.