Speciation analysis of Cr(III) and Cr(VI) in bread and breakfast cereals using species-specific isotope dilution and HPLC-ICP-MS

This study reports the development and validation of a analytical approach for simultaneous Cr(III) Cr(VI) speciation analysis in bread breakfast cereals using species specific isotope dilution (SS-ID) high-performance liquid chromatography (HPLC) coupled to inductively plasma-mass spectrometry (ICP-MS). The were extracted by sequential complexation genuine with ethylenediaminetetraacetic acid (EDTA) subsequently originating from reduction 1,5-diphenylcarbazone (DPCO) same run. Efficient HPLC separation Cr(III)-EDTA Cr(III)-DPCO complexes was carried out anion exchange less than 3 min. method validated means accuracy profile carrying measurement series duplicate on 5 different days over timespan one month. quantification limits 0.014 μg kg−1 0.047 Cr(VI), respectively. bias ranged 0.31 0.49 %, whereas coefficient variation terms repeatability (CVr) varied 1.3–4.4 % 0.6–7.9% Cr(VI). Similarly, intermediate reproducibility (CVR) 1.3–4.4% 2.0–8.9% successfully applied selection samples. not detected any these samples while levels between 5.2 176 23.8 350 kg-1 cereals. These results comparable total Cr analysed ICP-MS. developed this basis SS-ID is powerful tool accurate precise at trace allows correction interconversion during sample preparation.