Colorimetric determination of melamine in dairy products by Fe(3)O(4) magnetic nanoparticles-H(2)O(2)-ABTS detection system.

In this paper, a simple and rapid colorimetric method, which does not require any expensive and complex instruments, is established for the determination of melamine in dairy products. Lower than 2.5 ppm (the safety limit in the USA and EU) of melamine in real samples can be detected exactly with the recoveries in a range from 98-115% using a 721-A spectrophotometer. More significantly, the existence of melamine can be visually evaluated easily without the aid of any instrumentation.