Rapid slurry atomization using transverse heated electrothermal atomic absorption spectrometry for the determination of cadmium, copper, manganese and lead in biological reference materials

Abstract

A rapid slurry atomization procedure for the determination of Cd, Cu, Mn and Pb in certified reference materials such as GBW 08504 Cabbage, NIST SRM 1566a Oyster Tissue and NIST SRM 1571 Orchard Leaves is described using transverse heated electrothermal atomic absorption spectrometry. The slurry was prepared in 5% HNO₃ using a magnetic stirrer. No chemical modifier was used and the ashing step in the temperature programme was omitted. The atomization cycle was completed within 35–50 s. For Cd, Mn and Pb, aqueous calibration was used. For Cu, standard additions calibration was used. The Student’s t-test at the 95% confidence level was carried out on the results obtained and good agreement was observed as compared with the certified values. Stability tests on slurries in glycerol and HNO₃ indicated loss of Cd in glycerol in Cabbage as well as Oyster Tissue slurries. Pb was not stable in Cabbage slurry in 0.5% HNO₃ medium and Cu was not stable in Oyster Tissue slurry in glycerol. The limits of detection obtained were 0.0056, 0.066, 0.068 and 0.02 mg kg^–1 for Cd, Pb, Cu and Mn, respectively. The precision of the results obtained varied between 0.2 and 2% using a rapid atomization programme.