工作场所空气中二氧化硫测定方法的研究

Research on the determination of sulfur dioxide in the air of workplace

目的对现行国家标准中的二氧化硫甲醛缓冲液-盐酸副玫瑰苯胺分光光度法进行改进,提高测定结果的准确性。方法通过改变标准曲线量程;减少反应总体积,将原先要求在2支具塞比色管完成的反应合并在1支10 ml具塞比色管中完成;并且以在室温下直接反应取代在20℃恒温水浴中反应,同时对反应的时间进行一致性控制(通过控制从加液到测量吸光度的时间间隔来实现)。结果改进后的标准曲线,各点平行样之间较为集中,标准差较小,相关系数(r)>0.999。结论改进方法以后,标准曲线上各个点对应的吸光度值离散度较小,且平行样间相对允许误差小,改进后的方法同时扩大了标准系列的测定阶梯范围,扩大了实际检测的上下限,更能提高分析的准确度和精密度,使测定的结果更加接近样品真实值。

Objective To improve the current national standard of sulfur dioxide formaldehyde buffer-pararosaniline hydrochloride spectrophotometric method,so as to improve the accuracy of measurement results. Methods To change the standard curve range,reduce the total volume of the reaction,complete the merger in a 10 ml stoppered colorimetric tube compared with the originally requested in 2 stopper colorimetric reaction tube,in addition,to replace 20 ℃ water bath reaction with the directed reaction at room temperature,and to control the reaction times consistently（ by controlling the interval time from dosing to measure absorbance）. Results After being improved,more points were concentrated with each other in parallels,the standard deviation was smaller and the relative coefficient（ r） was〉 0. 999. Conclusion After the method improved,the absorbance value dispersion of each point which corresponded to the standard curve was smaller,and relative allowable error was also smaller among parallel samples. Additionaly the range of the standard series and the upper and lower limits of the actual testing were expanded,so that the accuracy and precision of analysis can be improved,and the detection results were closer to the true value of samples.