Colorimetric determination of 1-(4'-nitrophenyl)-2-aminopropane-1,3-diol with 2,4,6-trinitrobenzenesulfonic acid in the presence of chloramphenicol.

A colorimetric method based on the interaction between the chloramphenicol degradation product 1-(4'-nitrophenyl)-2-aminopropane-1,3-diol and the 2,4,6-trinitrobenzenesulfonic acid reagent was developed. Analytical solutions were reacted with the reagent at pH 9.1 for 20 min at room temperature, and the resulting color was measured at 340 nm. A linear relationship between absorbance and concentration occurred within the 5--25-micrograms/ml range under the conditions studied. Replicate analyses were in good agreement. An average recovery of 99.4 +/- 0.4% was obtained for the synthetic mixtures.