Functional group analysis of Suwannee River fulvic acid with reactive fluorescent probes

The reactive functional group content of Suwannee River fulvic acid (SRFA) was determined by reaction with fluorescent probes. Reaction with a triflate (R-SO2CF3) provided the total reactive group content in SRFA, and pyrene butanoic acid was used to determine the hydroxyl and amino groups. After purification of the product, standard addition analysis was used for quantification. The total reactive site content of SRFA was found to be 13.9 mmol/g, of which 57% were carboxylic acids, and 43% hydroxyl and amino groups. These values compare well with those obtained by other methods.