对顶空-气相色谱测定饮用水、烟笋、外婆菜和烤耳尖中亚硝酸含量进行研究,建立亚硝酸盐的快速、准确、定量检测方法,对该方法的反应机理进行推断,并用顶空-气质联用仪对反应产物进行验证.烟笋、外婆菜和烤耳尖经粉碎、沸水提取、沉淀剂沉淀和过滤后,取样品溶液分析,饮用水直接取样分析.样品处理液中先后加入环己基氨基磺酸钠溶液和硫酸溶液,在顶空瓶中50 ℃条件下发生重氮化反应,以衍生产物环己烯作为目标产物,定量分析.结果表明,低浓度标准物质标准曲线r2为0.999 0,取样量为5 mL时,对应的检测范围为0.001~0.200 mg/L;高浓度标准物质标准曲线r2为0.999 5,取样量为3 g时,对应的检测范围为0.67~167.00 mg/kg.该方法检出限低,线性范围宽,重复性和回收率好,是快速检测食品中亚硝酸盐较好的方法.%The determination of nitrite content in drinking water, smoked bamboo shoot, grandmother food and roasted ear tip was studied by using headspace-gas chromatography, and a fast, accurate and quantitative detection method of nitrite was established.The reaction mechanism of this method was deduced, and the relative products were validated by the headspace gas chromatography-mass spectrometry.The sample solution of smoked bamboo shoot, grandmother food and roasted ear tip were analyzed after crushing, boiling water extraction, precipitation and filtration, and then sodium cyclamate and sulfuric acid solution were added to pretreated sample.Diazo reaction was reacted in headspace bottle at 50 ℃, using the derivatives of cyclohexene as the target product and quantitative analysis.In this paper, the low concentration standard material standard curve r2 was 0.999 0.Moreover, the corresponding detection range was 0.001 ~ 0.200 mg/L when 5 mL sample was used.However, the high concentration standard material standard curve r2 was 0.999 5, and the corresponding detection range was 0.67~167.00 mg/kg while was 3 g sample was used.It was verified to be a good method for the detection of nitrite in food, with low detection limit, wide linear range, and good repeatability and recovery rate.
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