Accurate and Sensitive Analysis of Arsenic and Selenium in Foods
Introduction
Concern about the impact on public health from potentially toxic elements and
compounds present in everyday foodstuff has led to new legislative guidance. The
inorganic forms of arsenic (As) are known to be toxic and carcinogenic to humans,
and food and drink are a potential source of exposure [1]. To reduce the intake of
inorganic arsenic from the diet, the U.S. Food and Drug Administration (FDA)
proposed a new action level for inorganic arsenic in apple juice of 10 μg/L in 2013
[2,3]. Also, following the eighth meeting of the CODEX Committee on Contaminants
in Food, the World Health Organization (WHO) proposed a guideline for inorganic As
in polished rice of 0.2 mg/kg [4].
There is a clear need for reliable screening methods to accurately determine the
levels of such contaminants in food and drink products. The detection limits
required are low, as a 0.2 mg/kg limit equates to a digestate concentration of
2 μg/L (assuming a 100x digestion dilution). Even small errors in the precision and
accuracy of the analytical method could result in a food product being wrongly
classified as safe. Selenium (Se) is an essential micronutrient that can be deficient
in the diet as Se-poor soils yield Se-poor food crops. Accurate quantification of Se in
food is necessary to assess nutrient status.