对进出口食品中亚硫酸盐测定方法的改进研究

Study on the Improvement of Colorimetric Determination of Sulfites in Import and Export Food

对GB/T5009.34-2003《盐酸副玫瑰苯胺比色法》进行了一系列的改进研究。探讨了水不溶性固体样品的预处理方法,改进了SO2标准溶液的配制方法,同时研究了盐酸副玫瑰苯胺中盐酸的最佳浓度,以及有色物质中SO2含量的测定。结果表明,采用超声波处理水不溶性固体样品40 min大大提高了检测效率;改进后的配制方法,减少了标定的频率,并延长了SO2标准溶液的贮存时间;当盐酸副玫瑰苯胺中盐酸浓度为0.7mol/L时灵敏度高,线性良好;采用活性炭预处理有色物质,避免了假阳性结果的出现。改进后的方法缩短了检测时间,操作简捷易控、灵敏度高、重现性好,也扩大了该方法的适用范围。

This paper studied the traces of improvement of GB/T 5009.34-2003 hydrochloric para-rosaniline method.Investigated the pretreatment method of water-insoluble solid samples,improved the preparation of sulfite standard solution,and researched the optimum concentration of hydrochloride in the solution of pararosaniline hydrochloride,as well as the method for sulfite determination in colored substances.The results indicated that the detection efficientcy had significantly improved by using ultrasonic processing water-insoluble solid samples in 40 minutes.The improved preparation method can reduce the frequenty of calibration and extent the storage time of sulfite standard solution,when the hydrochloride acid was 0.7 mol/L in hydrochloric para-rosaniline with high sensitivity and good linearity.The use of activated carbon pretrement colored samples can avoid false positive results.The improved methods greatly shortened the testing time,easy to control,high sensitivity,good reproducibility,and also expanded the scope of application of the methods.