Determination of guanidino compounds by anion-exchange chromatography and amperometric detection

Guanidino compounds were separated and determined by anion-exchange chromatography and electrochemical detection using a basic aqueous eluent and a nickel working electrode. It was found necessary to use a sample clean-up procedure prior to chromatographic analysis of uremic dialysate and serum samples. The effect of eluent hydroxide concentration on the retention of guanidino compounds was studied. Quantitative calibration showed that working curves were non-linear. Electrochemical detection for guanidino compounds with a nickel working electrode, while not selective, has high detection sensitivity. Detection limits for guanidino compounds ranged from 3 to 12 pmol.