Popis: |
An HPLC-fluorescence (FL) method for determination of sulfur-containing amino acids such as homocysteine (Hcy), methionine (Met) and cysteine (Cys) in human plasma was developed. The sulfur-containing amino acids were labeled with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F). Calibration curves in the range of 1–100 µm (Hcy and Met) and 5–500 µm (Cys) indicated good linearities (r ≥ 0.998). The limits of detection at a signal-to-noise ratio of 3 were 0.13 (Hcy), 0.02 (Met) and 0.11 µm (Cys), respectively. Acceptable results for accuracy and precision of intra- and inter-day measurements were obtained. The results of Hcy and Cys obtained by the proposed method indicated good correlations with the conventional method (r > 0.911, n = 20). Furthermore, the method was applied to determination of the sulfur-containing amino acids in maternal plasma (n = 200) after delivery. The concentrations of Hcy, Met and Cys as a median (inter quartile range, Q1 and Q3) were 5.37 (3.32–7.79) μm, 25.20 (20.10–31.06) μm and 147.25 (102.81–189.31) μm, respectively. Copyright © 2012 John Wiley & Sons, Ltd. |