IC Determination of Thiocyanate in Liquid Dairy Products

Ion chromatography was applied to the determination of thiocyanate in liquid dairy product. The samples of fresh milk or sour milk were extracted with acetonitrile and purified on C18 SPE column. The protective column (Ion Pac AG11-HG) and separation column (Dionex ICS-3000) were used for separation, with 70 mmol·L-1 KOH solution as mobile phase, and conductivity detector was used in the determination. Linearity range was found between 0.20-10.0 mg·L-1, and detection limit (3S/N) was found to be 0.08 mg·L-1. The proposed method was applied to the analysis of fresh milk and sour milk, giving values of recovery in the range of 92.5%-104.5% with RSD′s (n=6)less than 4.5%.