A Rapid Flamephotometric Determination of a Microquantity of Sodium in Lead Metal

The determination of about 0.002 % Na in Pb metal by the CI curve method of the usual flamephotometric determination required about 2 days for its complicated procedures of removing the precipitate of PbSO4 and evaporating off the acids to dryness. A rapid method of determination based on the addition standard, linear extrapolation method carried out without removing the coexisting substances has been devised. The Pb as a principal constituent is removed as PbSO4instead of by spraying the sample solution because of the health hazard involved. Quantitative determinations of 3 kinds of Pb metal samples by this rapid method were carried out, and showed adequate accuracy. The results were in good agreement with those determined by heretofore known methods. An evaluation of the standard procedure of this method indicated that the time required for quantitative determination of a sample was 23hours by 2 analysts.