The use of diluted formic acid in sample preparation for macro- and microelements determination in foodstuff samples using ICP OES

A fast analytical method for determination of macro- and microelements in foodstuff samples by ICP OES using diluted organic acid extraction was developed. The sample preparation was carried out employing ultrapure 50% (v/v) formic acid on a heating block. The elements studied were Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn. The accuracy of the method was evaluated by analyzing three different certified reference materials (NIST (1577b) bovine liver, NIST (1515) apple leaves and NIST (8435) whole milk powder), and the recovery percentages ranged from 80.7 to 114%. The results obtained showed good agreement at a confidence level of 95% with the certified values, presenting RSD values < 20%. The limits of detection ranged from 0.056 mg/kg to 0.06 g/100 g. This solution-based method demonstrated the feasibility of using diluted organic acid, presenting high sample throughput and was considered simple and adequate for determining these analytes in foodstuff samples in routine analysis.