USE OF ELUENT CONTAINING SURFACTANT FOR THE LIQUID-CHROMATOGRAPHIC ANALYSIS OF PORPHYRINS BY DIRECT SERUM INJECTION

A gradient elution reversed-phase high-performance liquid chromatographic method was developed for the direct serum injection analysis of porphyrins based on the use of eluent containing an anionic surfactant (sodium dodecyl sulfate) at a concentration below the critical micelle concentration to elute the serum proteins at the column void volume. Separation and detection performances were tested with a mixture of porphyrin standards containing uro-, heptacarboxylic-, hexacarboxylic-, pentacarboxylic-, copro-, zinc proto- and mesoporphyrin in a model serum consisting of 50 mg/ml bovine serum albumin. Average limit of detection is 0.06 pmol with a 10-mul injection volume using fluorimetric excitation at the Soret band of porphyrins. The utility of this method for the direct serum injection analysis of porphyrins in human serum was evaluated by investigating serum samples from individuals suffering from iron-deficiency anemia and breast cancer.