Determination of different valence chromium in carrageenan vacant capsules by HPLC

To investigate whether the element chromium exsist in carrageenan vacant capsules and the valence of chrominum, EDTA was used to chelate trivalent chromium, and HPLC was used to detect the content of trivalent and hexavalent chromium in carrageenan vacant capsule with Thermo Dionex IonPacTMCS5A(4 μm× 250 mm)column, the mobile phase of 10 mmol/L anhydrous sodium sulfate solution, the flow rate of 1. 0 mL/min, and the detection wavelength of 242 nm. In this method, trivalent chromium and hexavelent chromium were separated. The linear range was 0. 2-40 μg/mL, Cr(III)linear equation was A=3. 96×10⁴c-1. 78×10⁴(r=0. 9991, n=8); Cr(VI)linear equation was A=1. 00×10⁵c+2. 97×10⁴(r=0. 9995, n=8), and the average recoveries were 98. 3%, 98. 7%, respectively. It suggested that this method was suitable for determination of content of trivalent and hexavalent chromium in carrageenan vacant capsules.