亚硝酸盐的快速检测

---

亚硝酸盐的快速检测

（亚硝酸盐速测管使用说明）

方法编号：CDC-1061

1. 食盐中亚硝酸盐的快速检测及食盐与亚硝酸盐的快速鉴别：用袋内附带小勺取食盐1平勺，加入到检测管中，加入蒸馏水或纯净水至1ml刻度处，盖上盖，将固体部分摇溶，10分钟后与标准色板对比，该色板上的数值乘上10即为食盐中亚硝酸盐的含量mg/ kg，（国标规定食盐（精盐）中亚硝酸盐的限量卫生标准应≤2 mg/kg）。当样品出现血红色且有沉淀产生或很快退色变成黄色时，可判定亚硝酸盐含量相当高，或样品本身就是亚硝酸盐。

2. 液体样品检测：直接取澄清液体样品1ml加入到检测管中，盖上盖，将试剂摇溶，10分钟后与标准色板对比，找出与检测管中溶液颜色相同的色阶，该色阶上的数值即为样品中亚硝酸盐（以NaNO₂计）的含量mg/L。如果亚硝酸盐的含量是以氮（N）为计算单位（如饮用水或水源水等），读取色阶上的数值后除以5即可。如果亚硝酸盐的含量是以亚硝酸根（NO₂-）为计算单位（如矿泉水、瓶装饮用纯净水等），读取色阶上的数值后除以3.28即可。

3. 乳浊样品检测：牛乳及豆桨可直接取1ml加入到检测管中，，盖上盖，将试剂摇溶，10分钟后与标准色板对比，找出与检测管中溶液颜色相同的色阶，该色阶上的数值乘以2即为样品中亚硝酸盐的近似含量mg/L。

4. 固体或半固体样品检测：取粉碎均匀的样品1.0g或1.0ml至10ml比色管中，加蒸馏水或去离子水（纯净水）至刻度，充分震摇后放置，取上清液（或过滤或离心得到的上清液）1.0ml加入到检测管中，盖上盖，将试剂摇溶，10分钟后与标准色板对比，该色板上的数值乘上10即为样品中亚硝酸盐的含量mg/ kg，L（以NaNO₂计）。如果测试结果超出色板上的最高值，可定量稀释后测定，并在计算结果时乘上稀释倍数（如从10ml比色管中取出1.0mL转入另一支10ml比色管中，加水至刻度，从中取1.0mL加入到检测管中测定，测试结果乘上100（稀释倍数）即为样品中亚硝酸盐的含量。

部分食品、饮用水中亚硝酸盐的限量标准参考值（以NaNO₂计）

品    名        限量标准mg/kg	品     名             限量标准mg/kg
食盐（精盐）、牛乳粉         ≤2	香肠（腊肠）香肚、酱腌菜、广式腊肉、火腿≤20
鲜肉类、鲜鱼类、粮食        ≤3	肉制品、火腿肠、灌肠类                  ≤30
蔬菜                        ≤4	其他肉类罐头、其他腌制罐头              ≤50
婴儿配方乳粉、鲜蛋类        ≤5	西式蒸煮、烟熏火腿及罐头、西式火腿罐头  ≤70
以N-计：生活饮用水≤1mg/L 以NO2-计：矿泉水≤0.005 mg/L，瓶装饮用纯净水≤0.002 mg/L

5 注意事项

5.1亚硝酸盐含量较高时，试剂显红色后不久会变为黄色，将黄色溶液再稀释放入另一新的速测管中又会显出红色，由此区分是亚硝酸盐还是食用盐。

5.2当样品反应后的颜色大于标准色板2.00mg/L色阶时，应将样品稀释后再测，计算结果时乘上稀释倍数。

5.3生活饮用水中常有亚硝酸盐存在，不宜作为测定用稀释液。

6 试剂质量控制

6.1将0.025、0.1、0.25、0.5、1、2、5mg/LNaNO₂标准溶液分别加入装有固体格林试剂的速测管，盖盖将试剂摇溶，10min后与标准色板进行对比，其含量与色板上的色阶标识含量应当相同或相近。

6.2 试剂常温避光保存，有效期18个月。

 

       

图像1. 水中的亚硝酸盐        图像2.牛乳中的亚硝酸盐

 

北京中卫食品卫生科技公司 北京艺卓恒信科贸有限公司荣誉出品

www.bjzw.com.cn

技术咨询：bjzw@vip.163.com

 

Introduction for Nitrite Test Tubes

1. The rapid detection of nitrite salt: Take 1 spoon of sample to the test tube, add distilled water or purified water to 1ml scale office, sealed cover and shake the solid part of the dissolution, after 10 minutes with standard color contrast, the value of the color board shall be multiplied by 10, the salt content of nitrite in mg / kg, (national standard salt (salt) nitrite the limited health standards should be≤ 2 mg / kg). When the sample appears red and there is precipitation in the blood or quickly fade into a yellow, it can determine a high nitrite content, or the sample itself is nitrite.

 

2. Liquid sample testing: Take clarify liquid sample 1ml to test tube, covered with lid, shake to dissolve reagents, standard color after 10 minutes, compared with the test tube to find the solution in the same color gamut, the Levels on the sample values shall nitrite (in NaNO2 dollars) content mg / L. If the content is based on nitrite nitrogen (N) as the unit (such as drinking water or water in the water, etc.), after reading the value on the color scale, the final number should be divided by 5. If the content of nitrite based on nitrite (NO2-) as the unit (such as mineral water, bottled drinking water, etc.), after reading the value on the color scale can be divided by 3.28.

 

3. Opaque sample test: milk and beans to take 1ml paddle directly to test tube, covered with lid, shake to dissolve reagents, standard color after 10 minutes, compared with the test tube to find the solution of the same color Levels of the color scale on the value shall be multiplied by 2, the approximate sample concentration of nitrite mg / L.

 

4. Solid or semi-solid sample test: take a uniform sample crushed 1.0g or 1.0ml to 10ml colorimetric tube, add distilled water or deionized water (pure water) to the mark placed after shaking, and the supernatant ( or filtration or centrifugation supernatant) 1.0ml added to the test tube, covered with lid, shake to dissolve reagents, 10 minutes compared with the standard color, the color board shall be the value multiplied by 10 samples in Central Asia Nitrate content mg / kg, L (to NaNO2 dollars). If the test results over the maximum value of outstanding board can be measured by dilution and multiplied in the calculation results of the dilution factor (eg, from 10ml remove 1.0mL cuvette into Another 10ml colorimetric tube, add water to scale in order to reap 1.0mL test tube to the determination of test results multiplied by 100 (dilution) is the nitrite content of the sample.

 

 

Description:

① there are small amounts of drinking water often can not be the determination of nitrite diluent.

② If the color of deep color and a precipitate produced or soon fade into pale yellow, indicating a high nitrite content of samples required to increase the dilution re-determination.

③ excessive sample should be repeated on the experiment, when sent to the laboratory conditions to accurate quantification.

④From light at room temperature for 18 months period, production date, see packaging.