Speciation of chromium in edible animal oils after microwave extraction and liquid chromatography inductively coupled plasma mass spectrometry

Speciation of chromium has been carried out using reversed phase HPLC and ICP-MS in tandem. Isocratic elution using 0.5 mmol L− 1 tetrabutyl ammonium phosphate (TBAP) and 0.3 mmol L− 1 EDTA in 1% methanol (pH 6.9) as mobile phase separated Cr(III) and Cr(VI) in less than 110 s. Spectral interferences in ICP-MS at m/z 52 and 53 were reduced using NH3 in the DRC. Detection limits were 0.045 and 0.052 ng Cr mL− 1 for Cr(III) and Cr(VI), respectively. This method has been applied to determine Cr compounds present in selected edible animal oils and NRCC SLRS-3 Riverine Water reference material. The animal oils selected are used for different applications including cooking. Chromium species were extracted from oils using microwave heating with 0.4% v/v HF and 2% Triton X-100 in mobile phase. HPLC-ICP-MS results showed good agreement with total chromium concentrations in extracts obtained by ICP-MS analysis. An unknown chromium compound was found in all oil samples with the absence of Cr(VI).