Determination of the Content of Fluorine and Chlorine in Inorganic Insulation Materials by Ion Chromatography

摘要

A fast and accurate method for simultaneous determination of the content of fluorine and chlorine in inorganic thermal insulation materials by ion chromatography was developed. The samples were cut into pieces of weight less than 40mg, washed with water as the extractant, heated for 30 min and then centrifuged, filtered through a 0.22 um microporous membrane, and the cation was removed using a SEP-H column. The solution was rinsed with 20/30 mM KOH as the mobile phase, separated by anion exchange column and then detected using a conductivity detector. The mass concentration of fluorine and chlorine in the range of 0.1-10mg/L was linearly related to their peak area, the detection limit of fluorine was 0.030mg/Land the detection limit of chlorine was 0.016mg/L. The relative standard deviations (n=6) of the three typical inorganic insulating materials (glass wool, rock wool and mineral wool) were less than 2.0% and the rate of recovery of fluoride and chloride ion was between 97% and 101%.The method had good accuracy and recovery rate. The absolute error of the measured value between ion chromatography and the national standard was less than 0.20%.The results showed that the method was suitable for the determination of the content of fluorine and chlorine in inorganic thermal insulation materials.