Laser fluorometric detection of porphyrin methyl esters for high-performance thin-layer chromatography

A new detection method is presented for the determination of porphyrins present in biological materials. Separation is accomplished by high-performance thin-layer chromatography after esterification of individual carboxylic acid porphyrins. Detection is achieved by utilizing one of the visible lines of an argon-ion laser for fluorometric excitation. Good selectivity and detectability are demonstrated for the determination of porphyrin profiles in human urine. The detection limits for uro-, heptacarboxy-, hexacarboxy-, pentacarboxy-, copro-, and mesoporphyrin methyl esters are in the 18-35 pg range.