“…However, as for the quantitative aspects of chromatography as applied to assay of local anesthetics after the compounds have been separated, they find elution techniques undesirable. The experiences reported in this paper and in previous publications (1,2) indicate that satisfactory quantitation of these nicthods requires the use of photoelectric densitometry, thereby eliminating the need for elution. Measurement of Total Color Density of Spots.-As stated above and in previous publications (1, 2) the total color densities of the reference and sample spots were compared by direct proportion.…”