SUBATOMOLE DETECTION OF AMINO-ACIDS BY CAPILLARY ELECTROPHORESIS BASED ON SEMICONDUCTOR-LASER FLUORESCENCE DETECTION

A pyronin succinimidyl ester fluorescent in the deep-red region is synthesized, whose absorption maximum and molar absorptivity are 663 nm and 8.2 x 10(4). respectively. This compound is used for fluorescence labeling of amino acids such as alanine, arginine, glycine, glutamic acid, and aspartic acid. The sample containing the labeled amino acids is separated by capillary electrophoresis and is detected by semiconductor laser fluorometry. A sheath flow cell is used for reduction of the light scatter from the cell wall. This compact and inexpensive analytical system allows detection of 0.8-4.5 attomole of amino acids.