Atomic Absorption for Trace Element Analysis in the Food and Beverage Industry

One of the fastest growing markets in food safety is China, mirrored by the continued growth of the Chinese gross domestic product. The Food Safety Law, passed in China in June 2009 to toughen penalties against manufacturers of mislabeled or tainted food, has significantly raised the food safety profile in this region and increased the trace elemental analysis of foodstuffs. China is the world’s largest exporter of fruit and vegetables, with meat, fish, and cereals such as rice contributing significantly to its exports.

The analysis of trace elements in food is important; some laboratories analyze more than 100 samples per day. Flame AA offers a simple, dedicated solution, and with the use of an intelligent online dilution system and autosampler, provides complete automation over several orders of magnitude. Flame and furnace systems can also be used as complementary techniques for the analysis of multiple elements in the same sample. For example, the global annual production of rice–the staple food of most Asian countries–is approximately 600 million tons. In rice, Flame AA can analyze essential elements such as manganese and zinc, while furnace AA can be used to ensure that toxic elements such as cadmium and lead are below legislative limits. A major benefit of furnace AA is the small sample volume required for analysis. Typically, only a few microliters of sample are needed, allowing minimal dilution on the original sample to achieve the best detection limits.

The unique elemental properties of mercury can make it difficult to analyze using standard flame and furnace methods. A continuous flow system with on-line mercury reduction and cold vapor generation, however, allows detection limits in the ppb range to be achieved. This is comparable to the detection limits achieved with inductively coupled plasma optical emission spectrometry, yet the fact that it is a simple and economical solution makes it accessible to laboratories worldwide. The method has been used for the analysis of mercury in fish. Minamata Bay, located in the Kumamoto Prefecture of Japan, had more than 10,000 individual cases of mercury poisoning following the disposal of mercury-contaminated wastewater into the local river. It was several years, however, before the effects were observed and the source of the contamination identified. Bioaccumulation of mercury in the marine food chain results in high levels in predatory fish such as tuna, leading to poisoning in humans.

To ensure the quality of products, protect the consumer health, and comply with safety regulations and standards, companies in the food and beverage industries must perform rigorous testing and real-time monitoring of trace elemental concentrations in their products. AA is an established, powerful, and cost-effective technique that analyzes trace elements in a simple, accurate, dependable, and rapid manner. The technique offers flame, furnace, and vapor capabilities in combination with preparative accessories and automation and provides versatile, robust, and reliable configurations for even the most challenging applications.

Hazel Dickson is atomic absorption applications specialist for Thermo Fisher Scientific, Cambridge, UK. Reach her at [email protected] or by phone at +44 (0) 1223 347 400.