亚硝酸盐快速检测试剂研究及其在酱腌菜中的应用

A Spectrophotometric Reagent for the Rapid Detection of Nitrite and Its Application to Pickles

为提高分光光度法在测定亚硝酸盐过程中的安全性和效率,研究适用于酱腌菜的亚硝酸盐快速检测试剂。与GB 5009.33—2016《食品中亚硝酸盐与硝酸盐的测定》的分光光度法(简称GB法)作对比,采用正交试验优化3组新型重氮-偶合试剂(氨基苯磺酸-盐酸萘乙二胺组(DS组)、对氨基苯乙酮-盐酸萘乙二胺组(DT组)、磺胺-盐酸萘乙二胺组(HA组))的最佳组合,并比较其检测性能和贮存稳定性。结果表明:优化后的3组试剂中,丁二酸、酒石酸和苹果酸均可有效代替GB法中的浓盐酸作酸性介质,检测时间缩短5~14 min,提高安全性和效率;DS组、HA组、DT组的检测线性范围分别为0.02~3、0.02~3、0.02~3.4μg/mL,检出限分别为0.82、0.51、0.76 mg/kg,低于GB法1 mg/kg的标准;DS组与GB法抗干扰能力相当,HA组和DT组较高于GB法;测定15种酱腌菜中的亚硝酸盐时,除含碘量较高的海带样品外,准确度大小关系如下:DT组(96.01%~99.60%)>HA组(93.82%~96.24%)>GB法(88.61%~92.66%)>DS组(84.04%~87.00%),相对标准偏差均小于5%,其中HA组和4℃的DT组均可稳定贮存40 d,检测性能优于DS组。综上说明使用DT组和HA组试剂可有效提高分光光度法的效率、安全性,适用于酱腌菜中亚硝酸盐的快速测定。

In order to improve the safety and efficiency of spectrophotometry in the determination of nitrite and its applicability to pickles,the spectrophotometric method specified in the Chinese national standard was modified by using three new diazo-coupling reagents:p-aminobenzene sulfonic acid/N-(1-naphthyl)ethylenediamine dihydrochloride(ASANED),p-aminoacetophenone/N-(1-naphthyl)ethylenediamine dihydrochloride(AAP-NED)and sulphanilamide/N-(1-naphthyl)ethylenediamine dihydrochloride(SN-NED)to replace the two-step reaction.For each diazo-coupling reagent,the operating conditions were optimized using an orthogonal array design,and the detection performance and storage stability of the diazo-coupling reagents were compared.The results showed that in the optimized ASA-NED,AAP-NED and SN-NED methods,succinic acid,tartaric acid,and malic acid respectively could replace concentrated hydrochloric acid as the acid medium,shortening the detection time by 5–14 min,and improving the safety and detection efficiency.The linear detection ranges of the ASA-NED,AAP-NED and SN-NED methods were 0.02–3,0.02–3 and 0.02–3.4μg/mL,and the detection limits were 0.82,0.51 and 0.76 mg/kg respectively,compared to 1 mg/kg for the traditional method.The AAP-NED method had comparable anti-interference capacity to that of the traditional method,and the AAP-NED and SN-NED methods were more resistant to interference than the traditional method.When the levels of nitrite in 15 kinds of pickle were detected by the four methods,except for high iodine kelp samples,the accuracy decreased as follows:AAP-NED(96.01%–99.60%)>SN-NED(93.82%–96.24%)>traditional(88.61%–92.66%)>ASA-NED(84.04%–87.00%),and the relative standard deviation(RSD)values were all less than 5%.SN-NED at all temperatures investigated and AAP-NED only at 4℃were stable for 40 days,having better detection applicability than ASA-NED.In conclusion,the efficiency and safety of spectrophotometry could be improved by using AAP-NED and SN-NED,which could be suitable for the rapid determination of nitrite in pickles.