食品安全检测引入第三方机制——首批三聚氰胺检测机构名录公布 谱尼测试榜上有名

为了确保乳制品生产企业对原料和产品进行批批检验,严把质量安全关,根据国家"处理三鹿牌婴幼儿奶粉事件"领导小组关于综合利用社会检测资源,开展针对乳品中"三聚氰胺"检测的决定,按照国家质量监督检验检疫总局的部署,国家认证认可监督管理委员会日前紧急在全国范围内对实验室获得资质认定(计量认证)的食品检测机构能否按照高效液相色谱法、液相色谱-质谱法、气相色谱-质谱法中的一种或多种检测方法开展"三聚氰胺"检测进行了核实,     

液相色谱-串联质谱法检测食品中氯酸盐和高氯酸盐含量

现阶段食品中检测出的氯酸盐和高氯酸盐的含量,已经远远超过安全标准规定的阈值,需要引起高度重视。液相色谱-串联质谱法具有良好的检测效果,可实现多目标物的同时测定,因此使用液相色谱-串联质谱法对食品中氯酸盐和高氯酸盐含量进行检测。通过选择检测样品、试剂和仪器,制备标准溶液和样品溶液,设定液相色谱条件和质谱条件,从标准曲线、加标回收率和精密度方面对检测方法进行验证,结果表明,液相色谱-串联质谱法能够准确检测食品中的氯酸盐和高氯酸盐含量,提高检测的灵敏度和精密度。     

不同基质中三聚氰胺分析方法的研究进展

三聚氰胺是一种生产氨基树脂和塑料的化学中介物,和甲醛结合使用可以生产三聚氰胺甲醛树脂以及三聚氰胺泡沫,它也是颜料黄150、肥料以及治疗非洲昏睡病的含砷药物的一种主要成分,它还是杀虫剂灭蝇胺的次要代谢产物,三聚氰胺作为是一种氮杂环有机化工原料,严禁添加在食品或动物饲料中.其测定方法包括重量法、电位滴定法、高效液相色谱-紫外或二极管阵列和串联质谱 (HPLC-UV,DAD,MS/MS) 检测方法、气相色谱-质谱法 (GC-MS)、离子色谱法、免疫学检测方法、毛细管区域电泳-电喷雾质谱、拉曼光谱法和超声辅助提取电喷雾质谱法等.涉及检测的样品基质有工业用纯度较高的原料、饲料、乳及乳制品、蛋、肉、土壤、植物蛋白制品、小麦粉及其制品等.本文对不同基质中的原理及各自的优缺点进行了概述.     

食品中三聚氰胺的快速检测方法

三聚氰胺是一种广泛用于塑料、造纸和肥料的化工原料,若添加到食品中并长期被人们摄入会严重影响到身体健康。目前,用于三聚氰胺检测的方法主要有:高效液相色谱法、液相色谱-质谱法、气相色谱-质谱法、电色谱仪检测法等,但是,这几种检测方法均需要采用氮气吹干仪,存在不能一次处理大量样品、有毒气体污染环境、消耗大量氮气的技术问题。本文创新了一种新的检测设备"真空离心浓缩仪",同时优化了检测方法,能够快速检测三聚氰胺,同时具有以下优点:可同时处理多个样品而不会导致交叉污染;可以回收甲醇等有毒气体,减少环境污染;回收的甲醇经蒸馏处理后可以重复使用,降低了成本。     

牛奶中三聚氰胺的表面增强拉曼光谱检测法与 国标检测法的比较

目的 比较表面增强拉曼光谱法与国标法检测牛奶中三聚氰胺。方法 分别用表面增强拉曼光谱法和国标法(液相色谱-质谱法)检测牛奶中的三聚氰胺。结果 表面增强拉曼光谱快检法与国家标准方法GB/T 22388-2008第二法 液相色谱-质谱/质谱法在阳性样品的判定上结论一致;表面增强拉曼光谱法的平均回收率和精密度分别为117.3%和13.2%,国标法的平均回收率和精密度分别为106.2%和8.9%。结论 表面增强拉曼光谱法适用于牛奶中三聚氰胺的快速筛查;进一步的定量分析需要用国标法。     

液相色谱-串联质谱法检测食品中托曲珠利的研究

托曲珠利长期施用可导致残留物积累,并通过食品链传播给消费者,影响消费者健康。通过液相色谱-串联质谱法可以迅速、准确、灵敏地对于食品中残留的托曲珠利进行检测。本文通过液相色谱-串联质谱法准确检测食品中的托曲珠利含量,降低基质效应对于食品检测工作的影响。     

食品接触材料及制品中芳香胺毒性与检测方法研究进展

综述了20种芳香胺的毒性、国内外对其在食品接触材料及制品中迁移的相关法规及检测标准,并讨论对比了气相色谱法、液相色谱法、液相色谱-质谱法、气相色谱-质谱法、实时直接分析质谱法五种检测方法的定量限、检出限、加标回收率等指标。     

食品中米酵菌酸测定方法研究进展

近年来因食品被米酵菌酸污染而导致中毒事件时有发生,本文对食品中米酵菌酸的测定方法进行综合性总结。从最初的薄层色谱法和分光光度法,发展到到高效液相色谱法、高效液相色谱串联质谱法,到最新的超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法进行综述,为以后的米酵菌酸测定方法的开发提供参考。     

2种方法检测乳粉中三聚氰胺的探讨及改进

根据GB/T 22388—2008第一法高效液相色谱法和第二法液相色谱-质谱/质谱法测定乳粉中三聚氰胺,乳粉经三氯乙酸和乙腈提取,阳离子交换固相萃取柱净化之后,经高效液相色谱法、液相色谱-质谱/质谱法测定,外标法定量。第一法存在操作步骤不完善,回收率较低的问题;第二法存在基质干扰,虽然采用基质空白配制标准工作液,但无法彻底消除基质效应,回收率较低。通过加标回收试验,探讨2种方法的不足,并分别提出2种方法的改进措施。     

乳制品中三聚氰胺的Varian 220-MS GC-MS/MS离子阱质谱仪检测

国标GB/T22388-2008《原料乳与乳制品中三聚氰胺检测方法》规定的三种仪器检测方法中,即高效液相色谱法(HPLC)、液相色谱-质谱/质谱法(LC-MS/MS)和气相色谱-质谱联用法(GC-MS,GC-MS/MS),GC-MS/MS方法能有效消除背景干扰,因而检测灵敏度较高。通过试验,瓦里安建立了一种可用于精确测定乳制品中三聚氰胺含量的气相色谱多级质谱联用检测方法。该方法利用了离子阱多级质谱技术,在奶粉和牛奶中的三聚氰胺加标回收率均在85.0%-110%之间,     

酶联免疫吸附法快速测定不同样品 基质中三聚氰胺

目的 探求不同样品基质中三聚氰胺残留量的快速检测方法.为快速筛查不同种类食品中非法添加三聚氰胺提供技术保障.方法 采用酶联免疫吸附法在奶制品(奶粉、液态奶)、成品饲料(鸡饲料、猪饲料)、饲料原料(鱼粉、肉骨粉、豆粕、麸皮)、肉类(鸡肉、猪肉、内脏)等样品基质中添加一定浓度的三聚氰胺进行测定,并对检测结果进行分析.结果 酶联免疫试剂盒对奶制品和肉类检出限均能达到1.0 mg/kg;对成品饲料基质中的三聚氰胺的检测,检出限可达到2 mg/kg,而对饲料原料中的三聚氰胺的检测,检出限都不能达到2 mg/kg.结论 对奶制品中的三聚氰胺检测完全符合我国的临时限量标准;对成品饲料中的三聚氰胺残留的检测同样符合其限量标准(2.5 mg/kg),而对饲料原料中的三聚氰胺的检测,由于不同基质中检出限不同,不能直接采用酶联免疫法进行快速筛查;酶联免疫法也适用于肉类中的三聚氰胺的检测.     

两种不同形式的固相萃取技术相结合测定复杂基质中的三聚氰胺

针对饲料、巧克力制品、肉制品等一些复杂基质,采用分散性固相萃取技术与固相萃取技术相结合的方法进行净化,然后由高效液相色谱技术对三聚氰胺的含量进行测定。结果表明：该方法能够有效去除复杂基质中的油脂、蛋白质等基体的干扰,降低三聚氰胺假阳性的概率;在0.5～8.0μg/mL 范围内线性良好,相关系数R＞ 0.9995,检出限为0.5mg/kg。     

Transfer of melamine from feed to milk and from milk to cheese and whey in lactating dairy cows fed single oral doses

A study was conducted to evaluate the excretion pattern, after a single oral dose, of melamine from feed into milk, and the subsequent transfer to cheese and whey. The transfer of cyanuric acid was also investigated. Twenty-four lactating Holstein cows were randomly allocated to 4 treatments and received single doses of melamine as follows: 0.05, 0.50, 5.00, and 50.00 g/cow for groups D1, D2, D3, and D4, respectively. Individual milk samples were collected for melamine and cyanuric acid analyses on d 1, 2, 3, 4, 5, and 7. Milk collected individually from the second milking after melamine ingestion was used to make cheese on a laboratory scale. Melamine and cyanuric acid were extracted using a solid-phase extraction cartridge, and analyses were carried out by liquid chromatography-mass spectrometry/mass spectrometry. Maximal melamine concentrations occurred between 6 and 18 h after treatment and increased with log dose (linear and quadratic), ranging from 0.019 to 35.105 mg/kg. More than 60% of the melamine that was transferred to the milk was observed within 30 h after melamine ingestion. Melamine was not detected (limit of detection was 0.002 mg/kg) in milk 5 d after treatment in group D1, and 7 d after treatment in groups D2, D3, and D4. Blood urea nitrogen was not influenced by melamine ingestion. During cheese making, melamine was transferred mainly to the whey fraction. Cyanuric acid was not detected in any of the samples (milk, cheese, or whey). The excretion pattern of melamine in milk and whey may represent a health concern when cows ingest more than 0.50 g of melamine/d. However, only at intake levels of 5 and 50 g/d did cheese exceed the limits as set forth by the European Union. The results confirmed that melamine contamination of milk and milk products may be related not only to direct contamination, but also to adulteration of animal feeds.     

动物性食品中三聚氰胺的残留及危害

三聚氰胺陆续在饲料和乳与乳制品中被检出,引起了公众对三聚氰胺的密切关注。为进一步了解三聚氰胺,就三聚氰胺在动物性食品中的污染来源、危害及其检测方法进行了阐述。     

三聚氰胺的毒性毒理及检测最新进展

三聚氰胺是用途广泛的化工原料,含氮量高达66%,被不法分子作为蛋白替代品添加到乳品、饲料中,导致婴幼儿、宠物患泌尿结石甚至死亡。本文对三聚氰胺及其同系物的理化性质、代谢、毒性毒理、检测最新进展全面综述,并对其添加原因进行初步分析。     

Determination of melamine concentrations in dairy samples

Melamine, a basic organic chemical intermediate, can cause renal failure because of the formation of insoluble melamine cyanurate crystals in the kidneys. This study examined a novel fluorescence spectrometry for the determination of trace melamine in dairy. The method was based on the inhibitory effect of melamine on the decolorizing reaction of the uncatalytic oxidation of acridine red by potassium permanganate in a sulfuric acid medium. The calibration graph was linear for melamine concentrations of 2.1 × 10^?4–1.6 mg/L, and a detection limit of 61.5 ng/L was obtained. The melamine was determined in dairy samples by the proposed method after liquid–liquid and solid phase extraction. The results correlated with the high-performance liquid chromatography. The recoveries were within the range of 99.6–103.3% for liquid milk and 98.5–111.1% for milk powder. The possible mechanism of the reaction was also investigated by ultraviolet spectra.     

Hot topic: Pathway confirmed for the transmission of melamine from feed to cow's milk

Eight lactating Holstein cows were randomly allotted to 2 groups in a trial to establish whether a pathway exists for the transmission of melamine from feed to milk. All cows received oat hay ad libitum and 15 kg of concentrate pellets per cow daily. The concentrate pellets contained either melamine-contaminated corn gluten meal of Chinese origin (melamine treatment) or locally produced melamine-free corn gluten meal (control treatment). Cows in the melamine treatment ingested 17.1 g of melamine per day. Cows were milked twice daily, and milk samples were taken once daily during the afternoon milking for melamine and milk component analyses. Melamine appeared in the milk within 8 h after first ingestion of the melamine containing pellets. Melamine concentration reached a maximum of 15.7 mg/kg within 56 h after first ingestion, with an excretion efficiency of approximately 2%. Milk solids and milk urea nitrogen were not affected by treatment. The melamine concentration dropped rapidly after changing all cows back to the control pellets, but melamine only declined to undetectable levels in the milk more than 6 d (152 h) after last ingestion of melamine. Results from the current trial are important to the feed and dairy industries because, until now, any melamine found in milk and milk products was attributed only to the deliberate external addition of melamine to these products, not to adulterated ingredients in animal feeds.     

The melamine adulteration scandal

Melamine, a nitrogen-rich chemical, has received much attention in recent years owing to a series of highly publicized food safety incidents. These include pet food recalls in North America in 2007 and the deaths of six infants and the illness of some 300,000 more in China in 2008 owing to the adulteration of milk, infant formula, and other milk-derived products. With contamination of human food and animal feed by melamine becoming a serious public health concern owing to its wide dissemination, there is an urgent need to understand why this scandal occurred and its consequences in depth. This review summarizes information relating to the manufacture, uses, occurrence and quantitative analysis of melamine and melamine analogues. Other sections deal with the unfolding of the melamine scandal and its aftermath, the toxicity and carcinogenicity of the compound and its analogues, interim safety measures and risk assessment.     

Detection of melamine using commercial enzyme-linked immunosorbent assay technology

Recent cases of adulteration with melamine have led to the need for rapid and reliable screening methods. To meet this need, commercial enzyme-linked immunosorbent assay (ELISA) test kits for the detection of triazines were evaluated. The recently released Melamine Plate kit (Abraxis, Warminster, Pa.) displayed a limit of detection of 9 ng/ml for melamine in phosphate-buffered saline (PBS) and approximately 1 microg/ml for melamine added to dog food. An atrazine ELISA test kit produced by Abraxis required 0.2 mg/ml to generate a response more than four times the standard deviation from background. In contrast, with the EnviroGard Triazine Plate kit (Strategic Diagnostics, Inc., Newark, Del.), 1.5 mg/ml melamine in PBS generated a signal only one standard deviation from background, which was insufficient to define a limit of detection. Extraction based on dilution with 105 mM sodium phosphate/75 mM NaCl/2.5% nonfat milk/0.05% Tween 20 (UD) enabled detection of fivefold less melamine in dog food than did use of the procedure recommended by the manufacturer, which entailed extraction into 60% methanol, sonication, centrifugation, filtration, and further dilution into 10% methanol/PBS. Using the Abraxis Melamine ELISA, both extraction protocols yielded identical results with a dog food sample adulterated with melamine. The recovery of melamine spiked into gravy from dog food using UD was 74% +/- 4%. In conclusion, the recently released Abraxis ELISA for melamine proved to be a useful alternative to more cumbersome methods.     

Potential of SERS for rapid detection of melamine and cyanuric acid extracted from milk

Melamine, a nitrogen-rich chemical, was implicated in the pet and human food recalls in 2007 and in the global food safety scares in 2008 involving milk and other milk-derived products. In this study, we investigated the feasibility of using surface-enhanced Raman spectroscopy (SERS) coupled with SERS-active gold substrates for rapid detection of trace amounts of melamine and its analogue (that is, cyanuric acid) in liquid milk. Raman signals of tested samples were significantly enhanced by SERS. The identification limit for SERS using gold substrate can reach 2 ppm of melamine in liquid milk. Partial least squares (PLS) models were established for the quantification of melamine in liquid milk by SERS: R = 0.90, RMSEP = 1.48 × 10⁻⁵. Our results demonstrate that rapid detection of melamine in milk can be achieved by SERS; while detection of cyanuric acid in milk remains a challenging task due to rapid enol-keto tautomerism of cyanuric acid. The SERS method is faster and simpler than other traditional methods, and requires minimum sample preparation. These results demonstrate that SERS could be used to detect food contaminants such as melamine in foods and food ingredients quickly and accurately.