IC Determination of Fluoride in Graphite

Sample of graphite was fused with NaOH at 500 ℃ and the melt obtained was dissolved with hot water. The content of F- in the sample solution was determined by IC. Dinoex AS15 chromatographic column was used as ion exchange column and 20 mmol·L-1 NaOH was used as eluent with conductivity detector for determination. Linear relationship between values of peak area and mass concentration of F- was obtained in the range of 0.01-1.0 mg·L-1. The proposed method has been used in the analysis of 14 samples of graphite from 4 area, giving the contents of F- in the range of 3.16×102-2.04×103mg·kg-1 with RSD′s (n=11) less than 3.0%.