Simultaneous Determination of Fluoride, Chloride, Sulfur and Nitrogen in Imported Petroleum Coke by IC with Pyrohydrolysis

IC was applied to the simultaneous determination of fluoride, chloride, sulfur and nitrogen in imported petroleum coke with pyrohydrolysis. The optimized conditions found were as follows:① combustion temperature of high heat was 1 100℃; ② flow of oxygen was 500 mL·min^-1; ③ evaporation capacity of water vapor was about 2 mL·min^-1; ④ amount of Na₂O₂ was 0.12 g. 30 mmol·L^-1 KOH solution was used as eluant, and restraining conductance detector was used in determination. Linear relationships between values of peak area and mass concentration of the 4 ions were all kept in definite ranges, with detection limits (3S/N) of the method in the range of 0.044-0.33 mg·L^-1. Values of recovery found by standard addition method were in the range of 80.0%-96.0%, and values of RSD's (n=6) were in the range of 2.9%-18%.