Sorption-spectrophotometry and chromaticity determination of some organic bases used in local anesthesia using Alizarin Red C

The use of 1,2-dihydroxyanthraquinone-3-sulfonic acid sodium salt, Alizarin Red C (ARC), is considered in application to the sorption-spectrophotometry determination of organic bases novocaine and lidocaine, used as local anesthetics. The optimal conditions for the formation of all adsorbates are deter-mined, and the equations depicting the relation between the chromaticity functions (CFs) and concentration of organic bases are found. As shown, ARC absorbs chemically on the surface of gamma-Al2O3 as ions with the charge 2- with a predominantly vertical orientation. The calculated molar coefficients of sorbates' CFs are 200 times hugher than the ones for respective extracts. Based on the developed procedures, color scales for the rapid testing of analytes are developed. The potential use of the procedures elaborated is discussed.