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有机磷类和氨基甲酸酯类农药的快速检测
(农药速测卡使用说明) 方法编号:CDC-1011

1 适用范围: 本方法适用于蔬菜、水果、相应食物、水及中毒残留物中有机磷类和氨基 甲酸酯类农药及鼠药的快速检测。本方法引自国家标准快速检测方法GB/T5009.199-2003。

2 检测原理:
有机磷或氨基甲酸脂类农药对胆碱酯酶有抑制作用, 可抑制胆碱酯酶试剂在特定条件下的显色状态,通过目视或仪器来判断样 品中是否含有有机磷类或氨基甲酸酯类农药的存在。

3 检测试材
3.1包被了胆碱酯酶等试剂的农药速测卡;
3.2农药提取(浸提)液;
3.3蔬菜整体测定法时需要0.1g感应量的天平;
3.4有条件时,可选用具有加热、定时程控程序的农药残毒速测仪。

4 蔬菜、水果中农药残留量的检测、结果判断与注意事项
4.1 表面测定法(粗筛法): 擦去蔬菜表面泥土,滴2~3滴浸提液在蔬菜表面,用另一片蔬菜在滴液处轻轻摩擦。取一片速测卡,将蔬菜上的液滴滴在白色药片上。放置10min进行预反应,将速测卡对折(红色药片与白色药片叠合)后,用手捏3min时,打开与空白对照实验卡比较,白色药片不变色或略有浅蓝色均为阳性结果。白色药片变为天蓝色或与空白对照卡相同为阴性结果。有条件时,将纸片插入“农药残留速测仪”自动恒温、定时检测。
4.2 整体测定法: 选取有代表性的蔬菜样品,擦去表面泥土,剪成1cm左右见方碎片,取5g放入带盖瓶中,加入10mL浸提液(样品与浸提液的比例为1+2),震摇50次(有条件时,可将提取瓶放入超声波提取器中震荡30秒),静置2min以上。取一片速测卡,在白色药片上滴上2~3滴提取液,放置10min进行预反应,将速测卡对折(红色药片与白色药片叠合)后,用手捏3min时,打开与空白对照实验卡比较,白色药片不变色或略有浅蓝色均为阳性结果。白色药片变为天蓝色或与空白对照卡相同为阴性结果。有条件时,将纸片插入“农药残留速测仪”自动恒温、定时观察。
4.3注意事项:
4.3.1 目前国内外所使用的农药残留测定方法(纸片法和分光光度法)的检验原理基本相同,测定中的干扰物质也基本相同。葱、蒜、萝卜、芹菜、香菜、茭白、蘑菇及番茄汁液中含有对酶有影响的植物次生物质,容易产生假阳性。处理这类样品时(包括含叶绿素较高的蔬菜),不要剪的太碎。测定番茄时,可将提取液放在茄蒂处浸泡2min,取浸泡液测定。测定韭菜或大蒜时,可整根或整粒放入容器中,加入提取液后振摇提取测定。
4.3.2 饮用水中的农药检测,可直接取2~3滴加到速测卡上进行操作。茶树上茶叶中的农药检测,可按本方法测定,加工后的茶叶,参照“相应食物及中毒残留物中农药的检测”。
4.3.3 检测样品的速测卡预反应放置的时间应与空白对照卡放置的时间尽量一致。红色药片与白色药片叠合反应的时间控制在3min,打开观察结果的时间应以1min内为准。
4.3.4 空白对照卡不变色的原因,一是有可能药片表面提取液加的少、预反应后的药片表面不够湿润;二是提取液(缓冲液)的酸碱度可能有问题(此时可用纯净水作对比确认);三是速测卡已过有效期。
4.3.5 在确定样品为有机磷或氨基甲酸酯类农药阳性结果时,应是重复多次检测的结果,必要时将样品送实验室用气相色谱仪或质谱仪进一步确定是哪种农药、确切含量。

5 相应食物及中毒残留物中农药的检测、结果判断与注意事项:
5.1样品处理与测定: 取样品适量于容器中,加入2倍量的乙酸乙酯,充分震摇后静置,取澄清液于蒸发皿中,在水浴上蒸干乙酸乙酯,取1mL磷酸盐浸提液溶解蒸干后的残渣,取残渣溶液2~3滴于速测卡白色药片上,放置10min进行预反应,将速测卡对折(红色药片与白色药片叠合),用手捏3min,打开速测卡,与同时操作的空白对照速测卡(白色药片上只加浸提液的速测卡)比较,白色药片不变色为强阳性结果,略有浅蓝色为弱阳性结果,天蓝色或与空白对照卡相同,为阴性结果。
5.2 注意事项:
5.2.1 在确定样品为有机磷或氨基甲酸酯类农药阳性结果时,应是重复多次检测的结果,对于中毒残留物,必需将样品送实验室用气相色谱仪或质谱仪进一步确定是哪种农药、确切含量。
5.2.2 其他注意事项与蔬菜、水果中农药残留量的测定注意事项相同。

6 农药速测卡的质量控制
6.1 按操作方法与注意事项进行,只加pH7.5磷酸盐浸提液或纯净水的农药 速测卡应变为蓝色;0.3mg/kg的敌敌畏或敌百虫溶液,可使农药速测 卡呈阳性反应。

7. 产品储藏与效期: 速测卡闭光常温保存有效期为1年。冷藏可延长有效期。




Rapid Test for Organophosphate and Carbamate Pesticides
1 Scope of application: This method is suitable for organophosphorus and carbamate pesticide detection in vegetables, fruits, appropriate food, water and toxic residues. It is taken from fast national standard detection methods GB/T5009.199-2003.

2 Detection principles

3 test specimens
3.1 Rapid detection of pesticides card
3.2 Ethyl acetate
3.3 pH7.5 phosphate extraction (buffer) solution: 15.0g disodium hydrogen phosphate were taken [Na2HPO4 • 12H2O] and 1.59g of potassium dihydrogen phosphate [KH2 PO4], with 500mL distilled water.
3.4 Balance
3.5 Rapid Test for pesticides designed "pesticide residues Tachometer" and ultrasonic extractor.

4 Fast tests of pesticide residues in vegetables and fruits. Judgment of the results and Notes.
4.1 Determination by the surface (coarse sieve method): vegetables, wipe the surface soil, drop 2 or 3 drops of extract in vegetable surface, with the other pieces of vegetables gently in the drip Department of friction. Take a quick test card, the vegetables on the liquid drops on the white pills. 10min placed pre-reaction, the Rapid Test Pack (red and white tablets pills superimposed), the Yong Shounie 3min, open the card compared with the control experiment; if the white tablets change into light blue or does not change color, then the results are positive. If the white tablet changes into blue or the same as the control card, then the result is negative. Conditionally, it will slip into "pesticide residues Tachometer" automatic thermostat, timing detection.
4.2 Determination by the whole: select representative samples of vegetables, wipe the surface of the soil, cut into 1cm square pieces around, take into Lid 5g bottle, add 10mL extract (extract of the sample and the ratio is 1 + 2), shake 50 times (conditional, can be extracted in the extractor bottle into the ultrasonic vibration for 30 seconds), stand more than 2min. Take a quick test card drops on the white pills on 2 to 3 drops of extract, pre-placement 10min reaction, the Rapid Test Pack (red and white tablets pills superimposed), the Yong Shounie 3min, open and empty control experiments card comparison, if the white tablets change into light blue or does not change color, then the results are positive. If the white tablet changes into blue or the same as the control card, then the result is negative. Conditionally, it will slip into "pesticide residues Tachometer" automatic thermostat, timing observation.
4.3 Note:
4.3.1 Using pesticide residue determination methods at home and abroad (disk diffusion method and spectrophotometry) are in the same test principle, determination of interfering substances are basically the same. Onion, garlic, radish, celery, parsley, water bamboo, mushrooms and tomato juice contains the enzyme affect plant secondary substances prone to false positives. When dealing with such samples (including those with high chlorophyll vegetables), do not cut in too broken. Determination of tomato, the eggplant can extract on the City Department soak 2min, get soaking solution was measured. Determination of chives or garlic, it can put the whole container, whole root, or by adding extract measured after the shaking extraction.
4.3.2 Detection of pesticides in drinking water can be directly added to take 2 to 3 drops of speed measurement card to operate. Tea on the detection of pesticides in tea, can be measured this way, processed tea, the light of "the corresponding residues in food and pesticide poisoning detection."
4.3.3 Detection Rapid Test samples placed in pre-reaction time should be placed with the control card as the same time. Red pills and white composite reaction time control pills in 3min, open observation time should be within 1min prevail.
4.3.4 control card does not change color because, first, tablets may increase the surface extract less, pre-reaction of the tablet surface moist enough; second extract (buffer) of pH may be a problem (when available pure water for comparison to confirm); Third, the operating environment in the air may contain pesticide residues.
4.3.5 In determining the sample of organic phosphorus or carbamate pesticides positive results, should be a repetition of the result of multiple detections, if necessary, the samples sent to the laboratory when using gas Se Pu Huo mass spectrometer instrument to further determine which Nongyao, the exact content.

5 The corresponding residues in food and pesticide poisoning, and the results determine and notes:
5.1 Sample handling and determination: to take the sample amount in the container, add 2 times the amount of ethyl acetate, after sufficient shaking standing, take mix with the pan in water bath on evaporation to dryness in ethyl acetate, to take 1mL phosphate extract after evaporation to dryness the residue dissolved, take 2 to 3 drops of solution residue on the white pills on a quick test card, placing 10min pre-reaction, the Rapid Test Pack (red and white tablets pills superimposed), hand pinching 3min, open the speed test card, and also control the operation speed test card (white tablet on an increase of only extract the Rapid Test) compared to white pills do not change color as the strong positive results, a slight light blue for the weak positive The results, sky blue or the same with the control card for the negative results.
5.2 Notes:
5.2.1 In determining the sample for the organophosphate or carbamate pesticides positive results, testing should be repeated many times the result of the poisoning, residues, essential to the sample sent to the laboratory using gas chromatography or mass spectrometry to further determine which pesticides, the exact content.
5.2.2 Other Considerations and vegetables and fruits in the determination of pesticide residues in the same note.

6 Pesticide quality control of Rapid Test:
6.1 How and attention issues, only add pH7.5 phosphate solution or pure water extraction of pesticides strain Rapid Test for the blue; 0.3mg/kg of dichlorvos, or trichlorfon solution, enables fast testing of pesticides card positive.

7. Product storage and Validity: Closed Light Rapid Test is valid for 1 year storage at room temperature. The storage can be extended by cold storage.

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