A DETERMINATION OF LEAD BY FLAME AAS

1 The sample is nebulised into an air-acetylene flame, where it is vaporised lead compounds are atomised and the lead atoms thus formed absorb radiation from a hollow cathode lamp. The absorbance is measured at a wavelength of 217.0 nm, using deuterium backgrourxl correction. 

1 This procedure yields a standard curve that is linear up to approximately 2 mg/L Pb. 

2 The detection limit is approximately 0.05 mg/L in the digest. The determination limit is approximately 0.15 mg/L (7.5-19 mg/kg in the dried plant material). 

1 To avoid interferences as much as possible, background correction is necessary. 

1 The reproducibility of determinations by this procedure should give, at reasonable control and thorough sample preparation, a coefficient of variation within 10 % -1-10 mg/kg. 

---