SOLVENT-EXTRACTION AND SENSITIVE ONE-DROPFLAME ATOMIC-ABSORPTION SPECTROMETRIC DETERMINATION OF LEACHABLE LEAD FROM LEAD-GLAZED CERAMICWARE

Low concentrations of lead leached from lead-glazed ceramicware into 4 % acetic acid were determined by the one-drop atomic absorption spectr ometry with a fuel-lean air-acetylene flame after the extraction of le ad pyrrolidin-1-yldithioformate into chloroform. To a glass test tube with a stopper, 5 ml (or 10 ml) of 4% acetic acid leachate and 1 ml (o r 2 ml) of 1 % ammonium pyrrolidinedithiocarbamate solution were taken and the mixture was shaken with 0.5 ml of chloroform 3 times for 10 s by hand. Direct nebulization of 50 mul of the chloroform extract of l ead complex gave a 3.9 times more sensitive signal height than that ob tained by nebulizing a 4% acetic acid solution. With this technique, l ead at 0.1 mug/ml levels in 4% acetic acid was easily determined witho ut background correction. This method was very simple and gave very go od reproducibility (RSD = 1.4 % at 3 mug/ml chloroform).