May 15, 2009
Researchers in Argentina have developed a new approach to testing food packaging for trace amounts of the toxic heavy metal cadmium.
Cadmium is one of several additives used extensively in the manufacture of plastics. Regulations limit the concentration of cadmium allowable, of course. In the European Union that limit is 100 milligrams per kilogram. But, the toxic metal has a long biological half-life (10 to 30 years) and so essentially accumulates in your body on repeated exposure.
Analytical advances aside, I asked Rodolfo Wuilloud of LISAMEN, how big a problem is cadmium in food packaging? Should the public be concerned?
“The presence of heavy metals in plastic food packaging is an important problem considering the extended use of this type of packaging,” he told me, “Concentration of heavy metals should be limited in order to reduce their potential health impact resulting from their possible migration from the packaging material into food and also to ensure that such substances are not released into the environment, for example in emissions or ash when packaging is incinerated, or in leachate when packaging is landfilled.”
He adds, that it is important that the public should be aware of this problem. Concern is the first step towards getting governments to change environmental policies. “It is necessary to introduce national measures to ensure that packaging is allowed on the market only if it complies with certain requirements in their composition so as to prevent the addition of noxious heavy metals to packaging and to reduce the impacts on the environment and human health,” Wuilloud’s colleague Estefania Martinis says.
The team used room temperature ionic liquids (RTILs) as an online pre-concentration medium for flame atomic absorption spectrometry analysis of trace cadmium in plastic food packaging materials. Critically, the use of non-volatile, non-flammable RTILs instead of volatile and flammable organic solvents is helping in this regard by allowing analytical scientists to breathe new life into powerful techniques, such as atomic absorption spectroscopy, that have been labelled “old fashioned” in recent years as other methods emerged.
Martinis, E., Olsina, R., Altamirano, J., & Wuilloud, R. (2009). On-line ionic liquid-based preconcentration system coupled to flame atomic absorption spectrometry for trace cadmium determination in plastic food packaging materials Talanta, 78 (3), 857-862 DOI: 10.1016/j.talanta.2008.12.051