Carefully Select Tools to Analyze Melamine, Dioxin

Numerous food contamination incidents in recent years have put food safety in the spotlight as never before. The obvious challenges of policing a global, interdependent food production network are prompting consumers to question food safety, governments to increase regulation, and food producers to search for new testing solutions. In light of public concern over food safety, heightened in particular by dioxins found in Irish pork and melamine found in infant formula made in China, government agencies and food processors are selecting instruments that can accurately identify contaminants in the global food supply.

A growing list of new testing mandates has made many traditional testing solutions and workflows obsolete. In 2006, Japan’s Positive List for agricultural chemical residues in foods increased the number of chemicals with minimum residue limits (MRLs) from 238 to 758; now the number is nearing 900.1 For lettuce alone, the European Union (EU) raised the number of chemical compounds with MRLs from 102 in 1999 to 435 in 2008. As a result, food producers have a growing list of requirements their workflows must provide: lower limits of detection (LOD), high-throughput screening capabilities, ease of use for quick adoption, and robust reporting and data management capabilities, to name a few.

Melamine and Dioxin Contamination

Two topical food safety issues that have recently hit the headlines are melamine and dioxins, both of which have been found in finished food products. Melamine is an industrial chemical that is used as a binding agent and flame retardant in the manufacturing of cooking utensils and plates. It has a high nitrogen content (66% by weight) and is used as a fertilizer in some parts of the world. It was added to animal feed as a cheap protein source in China before October 2008, and it was intentionally added to pet food and infant formula to mimic protein, despite never having been approved for pet and human food. Because humans and animals cannot metabolize melamine, a variety of illnesses result from its consumption. Melamine contamination has been linked to several deaths in China.

The toxicity of melamine results from the formation of insoluble crystals between melamine and cyanuric acid (a byproduct of melamine), which can cause the development of kidney stones in pets and babies. Besides melamine and cyanuric acid, two melamine-related compounds, ammeline and ammelide, were also found in adulterated pet food.

Due to the severe consequences of melamine adulteration in milk products, government food safety agencies around the world, including the General Administration of Quality Supervision, Inspection, and Quarantine of the People’s Republic of China, the U.S. Food and Drug Administration (FDA), and the U.K. Food Standards Agency have established limits of 1 mg/kg and 2.5 mg/kg MRL for melamine in baby formula and milk products, respectively.

Because it has been used as a fertilizer and was added to animal feed, other products may also have been contaminated by melamine. For example, eggs exported from China to Hong Kong were found to be contaminated by this compound. The testing list for melamine now extends beyond milk products or products with milk powder to meat, poultry, eggs, and vegetables.
Dioxins are another cause for concern in the food safety industry. Long-term exposure to dioxins, a group of chemicals formed during combustion processes like waste incineration, is known to increase the likelihood of cancer. In December 2008, the Irish government recalled all pork products originating in Ireland after the discovery of dioxins in slaughtered pigs. This recall was soon followed by an announcement from the Chinese government banning all imports of pork from Ireland after some of the meat was found to be contaminated with elevated levels of the chemicals.