Development and application of a method for Cr(III) determination in dairy products by HPLC–ICP-MS. (1st February 2018) - Hernandez, Fanny
Highlights: An "on-line" speciation method for Cr(III) in dairy products was developed. Cr(III) extraction assisted by microwave was optimised by experimental design. Interference corrections and analytical performances were evaluated. In all cases Cr(III) balanced Crtotal hence confirming the method accuracy. Abstract: This study describes the development of an analytical approach for the determination of Cr(III) in dairy products by microwave assisted extraction, complexation in situ by ethylenediaminetetraacetate (EDTA) and high performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry (HPLC–ICP-MS). The extraction step was optimised by using an experimental design. A limit of quantification of 38 µg kg −1 dry weight (d.w.) was obtained whereas the bias (%) measured ranged from 10 to 18%. The repeatability and intermediate precision varied between 1.2–5.0% and 7.5–13.5%, respectively. The method was applied to the analysis of several dairy samples beforehand characterized in terms of Cr(VI) and total chromium (Crtotal ). Cr(III) concentrations ranged from <13 to 255 µg kg −1 d.w. The results showed a good agreement between Cr(III) and Crtotal concentration levels.