Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1170646 | Analytica Chimica Acta | 2006 | 6 Pages |
A new analytical method for d-alanine (d-Ala) based on capillary electrophoretic separation and optical fiber light-emitting diode (LED)-induced fluorescence detection has been developed. Fluorescein isothiocyanate (FITC) was used for precolumn derivatization of amino acids. The separation and determination of the derivatives was performed using a novel laboratory-built CE system with optical fiber LED-induced fluorescence detector. Optimal separation was performed at 15 kV using a background electrolyte solution consisted of 25 mmol L−1 sodium borate (pH 9.5), 18 mmol L−1 β-CD and 15 mmol L−1 SDS. High sensitive detection was obtained by the optical fiber LED-induced fluorescence detection using a blue LED as the excitation source. The limits of detection (S/N = 3) for d-Ala was 8.0 × 10−9 mol L−1. A calibration curve ranging from 2.0 × 10−8 mol L−1 to 1.0 × 10−6 mol L−1 was shown to be linear. Using this method, the levels of d-Ala in human plasma from healthy donors were determined.