Determination of chromium(VI) and vanadium(V) using an on-line anodic stripping voltammetry flow cell with detection by inductively coupled plasma mass spectrometry

An on-line anodic stripping voltammetry (ASV) flow system, interfaced with an inductively coupled plasma mass spectrometric detector, was used to determine chromium(VI) and vanadium(V) and to eliminate polyatomic interferences which arise from sample matrices. The correct value was obtained for chromium in a certified water sample following oxidative pretreatment, using the conversion efficiency of Cr(III) to Cr-(VI) as a correction factor. Cr(III) in diluted NIST SRM 2670 urie resisted oxidative conversion prior to analysis, although spikes of Cr(VI) were determined in this medium (recovery 62%). Results for vanadium in diluted SRM 2670 wine using the standard addition method were in good agreement with the quoted noncertified value. V(V) spike recoveries were 43% in urine and 67% in water