Recently, from the University of California, Los Angeles, researchers and Wei Fang Cooperation Who developed a rapid, economic and simple method to detect Dairy products Or Food Whether with Melamine , Completed the test in just 15 minutes. The results were published in the international authoritative journal “Applied Physics Letters” on.
“Science and Technology Beijing newspaper”: What method is usually used to detect melamine?
Wei Fang: Melamine is a for Plastic And fertilizers, industrial materials, if mixed in the food in, will endanger human health, therefore, be quickly out from the test food is especially important. Currently, the most commonly used method is chromatography. As food molecules in the chemical and physical structure of different, so they detect the flow of media at different speeds. According to this theory, we can separate the melamine and other substances, then the measured value and the mass of melamine than the standard value to determine whether its content exceeded. Accuracy of this method is very high, far exceeding the state required minimum two millionths of the error limit. However, testing requires expensive and complicated equipment, simultaneous detection of a very long time, usually only used in a number of quality test centers.
There is also a commonly used method is enzyme-linked immunosorbent assay, the principle is the reaction of enzyme with melamine, produced during the testing of colored substances in quantitative and qualitative analysis. However, activity is, if the storage and transport in the event of a flawed process, will affect the test results, so for non-professionals in the operation very difficult.
“Beijing Science and Technology News”: The new record of 15 minutes of detection like?
Wei Fang: Our experiment Milk As the sample. Process is divided into three steps, including 5-12 minutes of the separation process, and less than 1 minute color precipitation reaction. First, may interfere with melamine test results in the separation of impurities from milk. Then, the solution particles. Gold nanoparticles can be minor to a few nanometers, to ensure that the milk of melamine molecules do not “slip through the net”, when it interacts with melamine, the color of the solution will lead to significant changes occurred. Finally, a cyanuric acid, the color of the nano-particle precipitation.
“Beijing Science and Technology News”: new ways to save time, but accuracy can guarantee?
Wei Fang: sensitivity of detection experiments measure the accuracy of one of its closely linked with the error. The higher the sensitivity, the smaller the error. The new method is convenient, the sensitivity was slightly lower than the traditional method, but still exceeded the national minimum error limit of 2 millionths. I think the significance of this method is not to replace the traditional methods, but provides a convenient way of screening. For example, the market or supermarket managers available in this convenient, compact devices are cleared quickly whether the melamine in food were determined.
“Beijing Science and Technology News”: The new method can applied in the public house?
Wei Fang: The new test method does not need the biggest advantage of professional equipment, eliminating the burdensome testing laboratory processes, the same time, test results can be read within 15 minutes, test results can be determined by the naked eye. We hope this research can quickly detect the spread in the family, and extended to test any food. At present, the dairy products, Eggs , Rice Protein concentrates and other foods have been found to contain melamine, the security situation is not optimistic. Hope in the near future, the new mother can use at home the gold particle detection, consumption of the baby milk and other baby foods, to ensure that does not contain melamine.