Formation and verification of the structure of the 1-fluorenylmethyl chloroformate derivative of sulfamethazine

Sulfamethazine (SMZ) is derivatized with 1-fluorenyl-methyl chloroformate (FMOC) to form the fluorescent adduct SMZ-FMOC, Conditions for formation are optimized with respect to pH, reagent concentration, and reagent ratio, Reagent and product profiles (including the hydrolysis byproduct FMOC-OH) versus time are followed by reversed phase HPLC with UV absorbance detection, FMOC-SMZ has been crystallized, its composition confirmed by microanalysis, and its structure corroborated by IR and NMR spectroscopy. From 10 down to ii ppm, there is clear gentle curvature in the fluorescence intensity of SRZ-FMOC. The linear response range extends from above 100 ppb down to about 100 ppt, and an increase in sensitivity for the fluorescent detection of FMOC-SMZ (over the usual UV absorbance detection of SMZ) is calculated to be better than 3 orders of magnitude.