On April 1, 2016, the US Food and Drug Administration (FDA) issued a Consumer Update, advising parents of its draft proposal to limit the presence of inorganic arsenic in infant rice cereals to 100 parts per billion, an action level comparable to the limit set by the European Commission (EU 2015/1006). This proposed policy change cites inorganic arsenic’s carcinogenicity (specifically its link to lung and bladder cancer) as well as growing concern that early childhood exposure could impact the achievement of developmental milestones.1 Indeed, for infants and children under three years of age, dietary exposure to arsenic from rice-based food products is two to three times the average adult exposure.2
Monitoring is an essential component of adherence to policies like the one recently proposed. In a recent webinar, Antonio Signes-Pastor from the Ricenic Project and Simon Nelms from Thermo Fisher Scientific addressed the application of Inductively coupled plasma mass spectrometry (ICP-MS) for the quantitation and speciation of arsenic in food products.2
While inorganic arsenic- As (III) and As (V)- are highly toxic, experts consider organic forms harmless. According to Nelms, measuring for total arsenic content can produce inflated results and lead to food waste. Speciation with chromatography allows researchers to separate inorganic arsenic from other species and more accurately reflect risk.
Nelms offered example applications of ICP-MS technology harnessed for this purpose. In one example, IC-ICP-MS effectively determined arsenic concentration in apple juice for six species: two inorganic (As (III) and As (V)) and four organic (arsenobetaine (AsB), arsenocholine (AsC), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA)). They found detection limits of 0.001 ng/g and 0.01 ng/g per species and 0.005 ng/g for total arsenic. For comparison, the maximum contaminant level set by the EPA for drinking water is 10 ng/g.
Another example application focused on organic brown rice syrup, a sweetening agent frequently used in toddler food, health foods, and energy products for endurance athletes. In that study, all three samples demonstrated arsenic levels above 100 µg/kg-1. Nelms indicated this is consistent with published data showing arsenic levels between 80 µg/kg-1 and 400 µg/kg-1 for this food product. Speciation revealed the most abundant species were As (III) for inorganic arsenic and DMA for organic arsenic. As (V) was also present.
In its Consumer Update, the FDA indicated that testing and reducing arsenic exposure for infants is feasible for producers, noting that 47% of the infant rice cereals they tested already met the proposed limit and 78% came close (at or below 110 parts per billion).1 With its high sensitivity and resultant low detection limits, IC-ICP-MS is a robust, efficient tool for the detection and speciation of trace elements like arsenic for food monitoring applications.
More information about ICP-MS technology and applications can be found here: thermofisher.com.
References
1 US Food & Drug Administration, “For Consumers: Seven Things Pregnant Women and Parents Need to Know About Arsenic in Rice and Rice Cereal,” 13 April 2016.
2 Nelms, S. & Signes-Pastor, A. Webinar: “Applying ICP-MS to Speciation and Quantitative Analysis of Arsenic in Foodstuffs and Beverages.” Separation Science, 18 April 2016.
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