Vanadium determination in milk by atomic absorption spectrometry with electrothermal atomisation using hot injection and preconcentration on the graphite tube

A sensitive method for vanadium determination in milk by atomic absorption spectrometry with electrothermal atomisation using hot injection and preconcentration in the graphite tube was developed. Three 30 µl portions of milk sample were injected into the heated graphite tube, inserting a drying and mineralisation step between each injection. Barium difluoride was used as a chemical modifier at a concentration of 100 mg l−1; with this modifier, vanadium was stable up to 2000 °C. The precision and accuracy of the method were investigated. The detection limit was 0.5, 0.7 and 0.6 µg l−1 for cows' milk, human milk and infant formulae, respectively. The method was applied to vanadium determination in 17 infant formulae samples, 13 human milk samples and 10 cows' milk samples.