IC Determination of Chromium(Ⅵ) in Polymers

Content of Cr(Ⅵ) in polymer materials was determined by IC. The polymer sample with granular size <250 μm was extracted for 3 h with 0.5 mol·L-1 NaOH solution. An appropriate aliquot of the extract was purified by filtration and passing through the RP column. IonPac AG19 protective column and DIONEX IonPac AS19 anion separation column were used for separation and 25 mmol·L-1 and 50 mmol·L-1 NaOH solutions were used for elution. Inhibitorty conductivity detection was adopted in the determination. Linear relationship between values of peak area and mass concentration of Cr(Ⅵ) was kept in the range of 0.10-10.0 mg·L-1 with detection limit (3s/k) of 7 mg·kg-1. Precision of the method was tested with the PVC sample for 8 determination, value of RSD found was 9.2%. Test for recovery was performed by standard addition method, giving recovery in the range of 95.2%-105%.