焦磷酸法测定粉尘中游离二氧化硅的方法优化和改进

Optimization and improvement of the jolt-phosphate method for determination of free silica in dust

通过优化和改进游离二氧化硅的检测方法,提高实验效率,减少操作误差。改进法在样品消化过程中选用数显陶瓷加热板精准控温,利用小型电子搅拌器替代人工对加热中的样品进行持续均匀搅拌。消化后的样品降温至100℃时,合并稀释和酸洗的步骤,直接加入60℃左右0.1 mol/L的盐酸至100 mL~150 mL,立即过滤。改进法与国标法同时测定质控样品和实际样品,结果显示两者相对偏差<8%;改进法精密度<5%,优于国标。改进法操作便捷,结果可靠精密度高,为日常样品检测提供了更高效的方法。

The improved method used a digital ceramic heating plate for precise temperature control during the sample digestion process.A small electronic stirrer was used to take the place of manual continuous and uniform mixing of the heated sample.After digestion,the sample was cooled to 100℃,and the dilution and acid washing steps were combined by directly adding approximately 0.1mol/L hydrochloric acid at around 60℃to 100-150mL of the sample,followed by immediate filtration.The improved method and the national standard method were used to measure quality control samples and actual samples,and the results showed a relative deviation of less than 8%between the two methods.The precision of the improved method was less than 5%,which was better than the national standard.The improved method is convenient to operate,and provides a more efficient method for daily sample detection with reliable and highly precise results.