883.    FAST, E.  Spectrographic Determination of Potassium in Iron Catalysts by Fractional Distillation.  Anal. Chem., vol. 22, 1950, pp. 320-322.

      Spectrographic method for determining K in Fe catalysts has been developed.  K was found to distill quantitatively from a sample pellet during the initial arcing period.  By photographing the spectrum during this period only, interference due to Fe was eliminated.  The length of the log sectored K line was found to be a linear function of the log concentration of K.  An average deviation of 5-10% of the amount present is indicated by repeated determinations on the same sample.  Na and Li can be determined in the same manner.  The method is not applicable to catalysts containing several percent of C.