Methods may include quantifying the concentration of residual free amine and/or free carboxylic acid in a product mixture prepared from a reaction of a multireactive species and a fatty reagent; verifying that the concentration for the free amine and/or free acid in the product mixture is within an acceptable threshold for a given application; and combining the product mixture with one or more wellbore fluid components to generate the wellbore fluid. In another aspect, methods may include including reacting the multireactive species and a fatty reactant to generate a product mixture; quantifying the concentration of residual free amine and/or free carboxylic acid in the product mixture; verifying that the concentration for the free amine and/or free acid in the product mixture is within an acceptable threshold for a given application; and collecting the product mixture.