Slurry-based procedures to determine chromium, nickel and vanadium in complex matrices by ETAAS

A unique slurry-based procedure to measure Cr, Ni and V could not be established. Cr concentrations up to 100 μg g− 1 were accurately determined by USS (0.5% HNO3; λ = 429.0 nm; LOD = 0.35 μg g− 1) whereas higher contents required the SE procedure (sample grinding, 30% HF; LOD = 0.02 μg g− 1). Both methods were appropriate to determine Ni (LOD = 0.11 and 0.08 μg g− 1, for USS and SE, respectively). V was satisfactorily quantified only with the USS approach (LOD = 0.80 μg g− 1).