外電報道：中國科學家發(fā)明檢測三聚氰胺的快捷新方法

     食品伙伴網報道，據(jù)美國食品安全新聞網8月10日消息稱，由中國衛(wèi)生部資助的科研小組于本周在同行評審期刊《Talanta》雜志上宣布：他們已發(fā)明了一種用以檢測牛乳制品中三聚氰胺的快速簡單變色的測試方法。

    在2008年爆發(fā)估計有30萬患兒及6例死亡病例的三聚氰胺奶粉丑聞后，該科研組開始研發(fā)測試方法。

    在文章中，研究者稱：他們開發(fā)出一種比色檢測方法，利用黃金納米粒子檢測產品是否被三聚氰胺污染。當被檢測的產品中存在三聚氰胺時，則納米粒子會互相接近并且聚集，而它們的顏色也從酒紅色變?yōu)樽仙蛩{色。這種方法對液體牛奶的檢出限為1.0ppm。對嬰兒幼兒配方奶粉的檢出限為4.2ppm。在使用紫外-可見分光光度法后，靈敏度提高，液體奶的檢出限為0.15ppm，嬰兒幼兒配方奶粉的檢出限為2.5ppm。這種測試可在30分鐘內完成，并且不需要預處理。所以研究者們稱這種方法適合對摻有三聚氰胺的乳制品進行現(xiàn)場檢驗。

    這種新的測試方法與現(xiàn)有的方法相比，具有更加快速且成本更低的優(yōu)點，并且不需要先進的一起或者固相檢查，但是其相對于其他測試方法來說，靈敏度相對要低一些。

    雖然其靈敏度較低，但是研究者稱，這種檢測方法的靈敏度已足夠監(jiān)管部門對乳制品中三聚氰胺水平的檢測了。

    據(jù)悉，在歐洲和美國，三聚氰胺的安全限制目前是2.5mg kg-1，而在中國，嬰兒配方食品為1mg kg-1，其他乳制品是2.5mg kg-1。

    原文報道:

New Test Detects Melamine in Milk Products

by Michelle Greenhalgh | Aug 10, 2010
This week Chinese scientists funded by the Chinese Ministry of Health announced in the peer-reviewed Talanta journal that they have developed a quick and simple color change test to detect melamine in milk products.

Scientists began working on developing a test after the contaminated milk scandal in 2008, when milk powder tainted with melamine sickened an estimated 300,000 people and killed six children.

In the article, scientists explained that they developed a colorimetric testing method that uses gold nanoparticles to determine whether or not the product is tainted. The test is designed so that when the nanoparticles approach each other and aggregate, their color changes from wine red to purple or blue. When melamine is present in the tested product, the aggregate approach process commences.

The new test can be used to test for melamine in infant formula and liquid milk with a detection limit of 1.0 ppm for liquid milk and 4.2 ppm for formula. The use of UV-vis-spectroscopy improves the sensitivity to 0.15 ppm in liauid milk and 2.5 ppm in infant formula.

The test can be completed within 30 minutes and does not require pretreatment. Study authors said, "The proposed method is promising for on-site screening of melamine adulterant in milk products."

The new testing method is praised by the scientists as faster, less costly than existing methods, and does not require advanced instruments or solid phase examination, but it is less sensitive than other tests.

Despite sensitivity issues, scientists claim that the test is sufficiently sensitive to detect melamine in milk-based products at levels desired by regulatory bodies.

In Europe and the US, melamine safety limits are 2.5mg kg-1 while the limit in China is 1mg kg-1 for infant formula and 2.5mg kg-1 for other dairy products.

原文地址：http://www.foodsafetynews.com/2010/08/new-test-detects-melamine-in-milk-products/