作业场所空气中氟化物滤膜采样方法的分析

Method analysis of fluoride sampling by filter membrane in the workplace air

目的分析滤膜采样方式对作业场所空气中氟化物浓度测定的影响。方法用K2HPO4浸渍玻璃纤维滤膜采集空气样品,以淋洗液Na2CO3-NaHCO3洗脱,用磁力搅拌器、超声波清洗器提取,取适量洗脱液经离子色谱分析,说明滤膜采样对作业场所空气中氟化物浓度测定的影响。结果采样的玻璃纤维滤膜选择K2HPO4浸渍液浸泡,分别以5 L/min流速采集空气75 L和1 L/min流速采集空气120 L,采样效率达100%,以磁力搅拌器搅拌5 min,超声波提取10 min,最佳洗脱效率为100%,采样稳定性好,9 d下降率<1%,方法的最低检测浓度可达0.0067 mg/m3,硫酸根离子等3种可能干扰物质对氟化物的测定不造成影响。结论该方法适用于作业场所空气中氟化物的采样监测要求。

[ Objective ] To analyze the effect of filter membrane sampling on the fluoride concentration determination in the work- place air. [ Methods] The workplace air was sampled by glass fiber filter impregnated with K2HPO4 , eluted by Na2CO3 -NaHCO3 so- lution, extracted with magnetic stirrer and ultrasonic cleaner, and then analyzed the effect of filter membrane sampling on the fluor- ide concentration determination through ion chromatography. [ Results] ] glass fiber filter impregnated with K2HPO4 were used to collect air 75 L at 5 L/min and 120 L at 1 L/min velocity separately with an efficiency to 100%. After 5 minutes＇ stirring , the sam- ple was extracted with ultrasound for 10 minutes. The best wash efficiency was 100% and the stability of sampling was good. The decline rate in 9 day was less than 1%. The lowest examination density of the sampling method was up to 0. 006 7 mg/m3. The three kinds of possible interference materials like sulfate ion were not able to influence fluoride measurement. [ Conclusion] This method meets the request of sampling of fluoride in the workplace air