Sensitive Linear Flowing-Stream Photometer for Amino Acid Analyzers

Publisher Website
Google Scholar
Abstract
A sensitive flowing‐stream photometer, [based on the photometric analyzer of Glasser, Kanzler, and Troy, Rev. Sci. Instr. 33, 1062 (1962)], with linear output suitable for monitoring the effluent from ion exchange columns after reaction with ninhydrin in the chromatographic analysis of amino acids, is described. Because of the linear output the analog display, in absorbance units, is printed on even grid paper on the strip chart recorder. The range is from 0 to 1.5 absorbance; at 2.5 absorbance the departure from linearity is 2.2%. The absorbance of the reaction stream at 4400 and 5700 Å is determined. At 5700 Å a split beam arrangement allows two levels of sensitivity to be recorded independently and simultaneously, each to any degree of attenuation below maximum so that a wide range of concentration can be accommodated. Drift and noise for the range 0 to 0.01 absorbance noise is approximately 2% of full scale, equivalent to 0.0002 absorbance. Other potential applications of the instrument include monitoring microbial growth and studying the kinetics of reactions whose time constants lie within the scope of the instrument. Demountable connectors allow the original dual wavelength mode of operation to be restored. In this mode the ratio of absorbance at two different wavelengths of a solute can be determined.