Y. Cheng, N. Dovichi
Oct 28, 1988
Citations
2
Influential Citations
437
Citations
Quality indicators
Journal
Science
Abstract
Subattomole analysis of fluorescein isothiocyanate (FITC) derivatives of amino acids is accomplished by combining capillary zone electrophoresis for high-efficiency separation with laser-induced fluorescence for high-sensitivity detection. Concentration detection limits range from 5 x 10(-12) molar for alanine to 9 x 10(-11) molar for lysine, injected in the column; 9 x 10(-21) mole of alanine is contained within the approximately 1-nanoliter injection volume at the detection limit. The alanine detection limit corresponds to fewer than 6000 molecules injected onto the column and represents an improvement of four orders of magnitude in the state of the art for fluorescent detection of amino acids and an improvement of six orders of magnitude in the state of the art for the detection limit for isothiocyanate derivatives of amino acids.