Researchers at the University of Johannesburg have developed a sensitive method to test for dangerous levels of heavy metals in some foods and water. The researchers said that it is possible to test for several metals at the same time, with the possibility for automation to be added. The instrumentation used is readily available in laboratories in developing countries, they noted.
Trace metals such as lead (Pb), arsenic (As), cadmium (Cd) and thallium (Tl) are toxic even at very low concentrations (levels). Arsenic, cadmium and chromium hexavalent compounds are also recognised as carcinogens by International Agency for Research on Cancer (IARC) and the US National Toxicology Program (NTP). “The study provides a simple, fast and sensitive method for laboratories with limited resources. The research results can also improve food quality for consumers,” said lead author Professor Philiswa Nomngongo, SARChI Chair, Nanotechnology for Water at the University of Johannesburg. “This study contributes data that can be used as a reference when setting up or revising the guidelines for the maximum allowable levels in common vegetables and palatable water,” she added. “The method is environmentally friendly and conforms to green analytical chemistry principles. It does not introduce secondary pollution.”
The researchers explained that labs often cannot directly measure some trace metals in foods, because they occur in ‘too low doses’. This means that sophisticated methods and sometimes expensive equipment are needed to detect the presence of some trace metals. They also noted that vegetables are inherently very complex to accurately analyse for chemical elements, creating long, time-consuming procedures to prepare samples to be ready for metals testing.
Source: New Food Magazine
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