Melamine Contamination Analysis

Melamine is an organic compound, which contains 67% nitrogen by weight. Heating dicyandiamide or urea in the presence of ammonia is one of the most common way to manufacture melamine on a large scale. It is generally considered that melamine can be hydrolyzed to several derivates, including ammeline, ammelide, and cyanuric acid.

Figure 1. Chemical structure of melamine and related food products

Melamine is often combined with formaldehyde to be used in the manufacturing of plastics and has a wide application in industry uses. Melamine can also be used in the fertilizer for crops on the farm. The melamine residual on the plants can take time to degrade. The mitigation of melamine from the plastic or the environment is minimal.

One major source for melamine getting into the foods is through illegal addition. Currently no approved regulations exist on the use of melamine in foods. Some illegal merchants found the adulteration of melamine or related compounds in infant formula and pet foods could increase the protein content of the food products due to its high level of nitrogen.

Melamine can cause serious health impacts on human beings. Melamine in the human body can be harmful to the reproductive system. It can also cause damage to the skin or eyes. Melamine cannot be metabolized and eliminated quickly by human body through urine. The accumulation melamine may contribute to the bladder cancer. Melamine has been considered as having carcinogenicity under conditions by the International Agency for Research on Cancer (IARC).

The United Nations' food standard body has specified the limit of melamine in powdered infant formula. The standard was set as 1 mg/kg (ppm). The standard for other food products and animal feed was set as 2.5 mg/kg (ppm).

Considering melamine and related compound molecules are small and polar, liquid extraction method is always suggested for initial melamine extraction. The step is usually followed by a clean-up procedure to remove potential interferences from co-extracted compounds. Then the determination of melamine in food matrices using appropriate analytical tools is performed. We have expertise in sample preparation of a variety types of food matrices.

We provide services for melamine testing as well as its homologus compounds such as ammelide, ammeline and cyanuric acid. We offer accurate and validated analytical methods that have been widely applied in the determination of melamine in food samples and animal feed to meet customers' needs.

Gas chromatography coupled to Mass spectrometry (GC-MS)

GC-MS is the official FDA method for the analysis of melamine as well as its other structural related compounds such as cyanuric acid, ammelide, and ammeline. Melamine can be detected in the range of ppm. The limit of detection for melamine is 2 mg/kg (ppm).

Liquid chromatography coupled to Mass spectrometry (LC-MS)

LC-MS is more sensitive and applied to analyze dairy products and infant food. Melamine can be detected in the range of ppm. The limit of quantification for melamine is less than 0.1 mg/kg (ppm).

We also maintain high quality assurance for the analysis. The recovery of internal standard, the use of blanks and spikes is monitored for each batch of analysis.