Lin Li

Publications (3)3.89 Total impact

• Article: Quantification of glutathione in plasma samples by HPLC using 4-fluoro-7-nitrobenzofurazan as a fluorescent labeling reagent.

  Xifeng Wang, Defeng Chi, Dajun Song, Guanmin Su, Lin Li, Lihua Shao
  [show abstract] [hide abstract]
  ABSTRACT: A rapid and highly sensitive high-performance liquid chromatograpy method with fluorescence detection has been developed for determination of glutathione (GSH) in human plasma. A simple pre-column derivatization procedure with 7-flouro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F) reagent was employed. The separation of the derivatized glutathione was performed using a mobile phase consisting of phosphate buffer (0.02 mol/L, pH 6.0)-acetonitrile (77:23, v/v) at a flow rate of 1.0 mL/min with the column temperature 2°C. The eluted derivatives were fluorometrically detected at an excitation wavelength 470 nm and an emission wavelength 530 nm. Under the optimum chromatographic conditions, the calibration curve was linear over the range of 0.1 µmol/L to 10.0 µmol/L with the correlation coefficient of 0.9988. The precision of the method was satisfactory with the intra- and inter-day coefficient of variation being 6.3%, 6.9%, respectively. This method has been used to determine glutathione concentrations in plasma samples from healthy individuals.
  Journal of chromatographic science 02/2012; 50(2):119-22. · 0.88 Impact Factor
• Article: Improved determination of D-glucosamine hydrochloride in health foods by HPLC using 7-fluoro-4-nitrobenzo-2-oxa-l,3-diazole as a derivative.

  Guanmin Su, Xifeng Wang, Defeng Chi, Lin Li, Lihua Shao
  [show abstract] [hide abstract]
  ABSTRACT: This article presents an improved method to detect D-glucosamine hydrochloride in health foods. A simple precolumn derivatization procedure with 7-flouro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F) reagent was employed. The separation of the derivatized D-glucosamine hydrochloride (NBD-D-glucosamine hydrochloride) was performed using a mobile phase consisting of acetonitrile, potassium dihydrogen phosphate (0.01 mol/L), and trifluoroacetic acid (350:649.74:0.26, volume ratio) at a flow rate of 1.0 mL/min with the column temperature 35 °C. Under the optimum chromatographic conditions, the peak area of NBD-D-glucosamine hydrochloride compared with its absolute value of the peak area of NBD-D-glucosamine hydrochloride in a standard solution concentration range from 1.0 to 500.0 mg/L showed a good linear calibration (R = 0.9999). Recoveries, at spiked concentrations of 10.0, 40.0, and 500.0 mg/L, varied between 97.2% and 102.6% with relative standard deviations ranging from 0.4% to 1.5%. The present method provides sufficient sensitivity as reflected by the values of limit of detection (LOD) and limit of quantification (LOQ). LOD was determined from the signal-to-noise ratios (S/N) of NBD-D-glucosamine hydrochloride peak of at least 3 in the recovery test at 0.02 mg/L, and the estimated LOQ was 0.06 mg/L (S/N = 10). The proposed method was successfully applicable to detect D-glucosamine hydrochloride in health foods and drugs containing a variety of complex materials.
  Journal of Food Science 11/2011; 76(9):N74-8. · 1.66 Impact Factor
• Article: Determination of taurine in biological samples by high-performance liquid chromatography using 4-fluoro-7-nitrobenzofurazan as a derivatizing agent.

  XiFeng Wang, DeFeng Chi, GuanMin Su, Lin Li, LiHua Shao
  [show abstract] [hide abstract]
  ABSTRACT: A highly sensitive and rapid high-performance liquid chromatography method with pre-column derivatization with 4-fluoro-7-nitrobenzofurazan was developed for determination of taurine in biological samples, including plasma, brain, and liver. The optimum derivatization reaction temperature was 70 °C, and at this temperature the reaction was complete within 3 min. The derivatized taurine was separated using phosphate buffer (0.02 mol/L, pH 6.0):acetonitrile (84:16, v/v) as the mobile phase at a flow rate of 1.0 mL/min, and a column temperature of 25 °C. The taurine derivatives were separated within 20 min (tR:14.5 min) and fluorometrically detected at 530 nm with excitation at 470 nm. The intra- and the inter-day coefficients of variation for the method were 5.3% and 7.7%, respectively. The calibration curve was linear from 0.1 μmol/L to 30.0 μmol/L with a correlation coefficient of 0.9995. This method can be used to determine the taurine contents in plasma, brain, and liver from normal rats and human plasma.
  Biomedical and Environmental Sciences 10/2011; 24(5):537-42. · 1.35 Impact Factor