The most interesting PCAs are 1,2,3,4-butanetetracarboxylic acid (BTCA) and citric acid (CA).
Since, to date, no analytical method is available to determine both qualitatively and quantitatively the amount of these cross-linking agents that have reacted with the cellulosic material, isocratic HPLC was applied to evaluate the nonformaldehyde finishing agent linked to the cellulose.