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 accuracy of the determination results by improving the pararosine hydrochloride spectrophotometry of formaldehyde dioxide in the current national standard. Methods By changing the standard curve range and reducing the total volume of the reaction, the reaction previously required to complete the two cuvettes was performed in one 10 ml cuvette; and the reaction was replaced by a direct reaction at room temperature ° C in a constant temperature water bath, with consistent control over the reaction time (by controlling the time interval from addition to measurement of absorbance). The results of the improved standard curve, each sample was more concentrated between the parallel samples, the standard deviation is smaller, the correlation coefficient (r)> 0.999. Conclusion After the improvement, the discreteness of absorbance value corresponding to each point on the standard curve is small, and the relative allowable error of parallel samples is small. The improved method also expands the range of standard series of measurement steps, expands the upper and lower limits of actual detection, More to improve the accuracy and precision of the analysis, the determination of the results closer to the true value of the sample.