Zinc determination in Tannat wine by direct injection onto graphite tube: Electrothermal AAS as an alternative to flame AAS

The method is based on the atomic absorption of zinc at the alternate resonance wavelength of 307.6 nm. Samples are injected in the graphite furnace without preparation and the determination carried out by SAM. Quantification limit was 0.10 mg L− 1 and linearity was confirmed in the range 0.10-10 mg L− 1. Precision (repeatability, sr (%), n = 5) was calculated at three concentration levels and found to be better than 5%. When compared with the OIV reference method, results agreed within 10%. The method is fit for the purpose of routine analytical quality control, requiring no sample preparation and thus less labour and producing less chemical waste.