Microplate photometric determination of aldehydes in disinfectant solutions

Microplate photometric analysis has been carried out to investigate the suitability of two chemically different methods based on N-methylbenzo-thiazolon-(2)-hydrazone and 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole for the determination of aldehydes in disinfectant solutions. The microplate methods have been developed and characterized with regard to their limits of detection and the stability of the reaction products. Special focus has been directed to the specificity of the reactions for different groups of aldehydes. Comparative measurements with the well-established and selective 2,4-dinitro-phenyl-hydrazine method as an independent and selective liquid chromatographic technique have been carried out. Dialdehydes such as glyoxal, succinic dialdehyde or glutaraldehyde, which are typical components of disinfectant mixtures, exhibited interesting reactions with the reagents.