The determination of vanadium in brines by atomic absorption spectroscopy

A standard addition method is described for the determination of vanadium in brines by atomic absorption spectroscopy with a nitrous oxide-acetylene flame. Sample pH is adjusted to 1.0 with concentrated hydrochloric acid and the vanadium is directly extracted with 5% cupferron in methyl isobutyl ketone (MIBK). The ketone layer is then aspirated into the flame and the recorded absorption values are plotted as a function of the concentration of the added metal. As little as 2.5 μg l⁻¹ of vanadium can be detected under the conditions of the procedure. Tungsten and tin interfere when present in excess of 5 and 10 μg ml⁻¹, respectively. The concentrations of the two interfering ions normally found in brines are well below interference levels.