INTERLABORATORY COMPARISON OF ABSORPTION SPECTRA BY THE PHOTOELECTRIC SPECTROPHOTOMETRIC METHOD.—DETERMINATIONS ON CHLOROPHYLL AND WEIGERT'S SOLUTIONS

Abstract

Solns. of chlorophyll a, solid chlorophylls a and b, and Weigert''s soln. were exchanged between 2 laboratories employing a double monochromator optical system in their photoelectric spectrophotometers. Numerical tables are presented to show the agreement attained, which was especially good for chlorophyll. This comparative study indicates the agreement of results obtainable by photoelectric spectrophotometric procedure on 2 different instruments and that discrepancies in the chlorophyll absorption are relatively minor in comparison with those reported during the last 10 years.