Aluminium is the third most abundant element within the Earth’s crust, making this element often occur in foodstuffs. Its presence in food can stem from natural occurrences, the use of aluminium-containing food additives, and from the usage of food contact materials with aluminium content. Primary contributors to the dietary aluminium intake include cereal and cereal products, vegetables, and beverages. The European Food Safety Authority (EFSA) recommends a Tolerable Weekly Intake (TWI) of 1 milligram aluminium per kilogram of body weight per week.[1] To regulate the content of aluminium in foodstuffs, it is necessary to accurately measure aluminium levels.
In our laboratory, we have developed a method utilising inductively coupled plasma optical emission spectroscopy (ICP-OES) to analyse certain elements (i.e. copper, iron, manganese, and zinc) in foodstuffs. To expand the scope of this method, a validation was carried out for the measurement of aluminium in food of vegetable origin. Compared to other metals, the full digestion of aluminium in food of vegetable origin requires higher temperatures. In addition, to avoid losses by evaporation due to these high temperatures, the dilution process needed to be optimized. These modifications were implemented compared to the initial digestion method to improve the accuracy of the aluminium measurements. Validation of the aluminium measurement using ICP-OES was performed, during which the precision, trueness and quantification limits (LOQ) of the measurement were determined. An expanded measurement uncertainty could be calculated.
Keywords: validation, aluminium, ICP-OES
References:
1. European Food Safety Authority (EFSA),. “Safety of Aluminium from Dietary Intake - Scientific Opinion of the Panel on Food Additives, Flavourings, Processing Aids and Food Contact Materials (AFC).” EFSA Journal 6, no. 7 (2008): 754. https://doi.org/10.2903/j.efsa.2008.754.
