论文部分内容阅读
目的通过优化比色法反应条件,建立比色分光光度法测定天花粉中二氧化硫的残留量。运用试剂盒法、比色法、顶空气相色谱法验证,探讨这3种方法测定结果的相关性。方法采用紫外分光光度法测定试验最佳吸收波长;利用响应面分析法对影响含量的因素进行优化,在单因素试验的基础上选取试验因素与水平,根据中心复合设计试验原理,采用四因素三水平的响应面分析法确定最佳比色法反应条件。结果确定最佳吸收波长为560 nm;最佳比色法反应条件:氨基磺酸铵溶液、氢氧化钠溶液、盐酸副玫瑰苯胺溶液用量分别为0.5、1.0、1.0 mL;反应时间为15 min。在该反应条件下,二氧化硫残留量在1.0~50.0μg与峰面积线性关系良好,r=0.9998;平均回收率为104.5%~105.3%,RSD为0.30%。结论该方法操作简便,重现性好,线性范围宽,可为天花粉及其相关加工产品中二氧化硫残留量的测定提供参考。
OBJECTIVE To establish a colorimetric spectrophotometric method for the determination of residual SO2 in TCS by optimizing the reaction conditions of colorimetric method. Using kit method, colorimetric method, headspace gas chromatography validation, to explore the correlation between these three methods to determine the results. Methods The optimal absorption wavelength was determined by UV spectrophotometry. The factors influencing the content were optimized by response surface analysis. Based on the single factor test, the factors and levels of the experiment were selected. According to the principle of composite design and test, Horizontal response surface analysis to determine optimal colorimetric reaction conditions. The results showed that the optimum absorption wavelength was 560 nm. The optimum conditions for colorimetric reaction were as follows: ammonium sulfamate solution, sodium hydroxide solution and pararosaniline hydrochloride solution were 0.5, 1.0 and 1.0 mL, respectively. The reaction time was 15 min. The reaction conditions, the residual amount of sulfur dioxide in the range of 1.0 ~ 50.0μg and the peak area of a good linear relationship, r = 0.9998; average recovery of 104.5% ~ 105.3%, RSD 0.30%. Conclusion The method is simple, reproducible and has a wide linear range. It can provide a reference for the determination of residual SO2 in TCS and its related products.