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 mu l 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 degrees C. The precision and accuracy of the method were investigated. The detection limit was 0.5, 0.7 and 0.6 mu g 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.