Yi Li,Jinhui Zhou,Xiaofeng Xue,Liming Wu,Lanzhen Chen,Jinzhen Zhang,Shuming Yang
An optimization method of NBD-F derivatization has been developed for the determination of proline in honey using high performance liquid chromatography (HPLC) with fluorescence detection. To determine the free proline in different samples of honey, ultrasound extraction was performed using 0.1 M borate buffer solution as the extraction solvent. Chromatographic separation was performed on a XDB C18 column (150 × 4.6 mm i.d.) using 0.1 M sodium acetate buffer solution (pH 7.2) : methanol : tetrahydrofuran (900 : 95 : 5, respectively, v/v/v) as mobile phase A and methanol as mobile phase B at a flow rate of 1.0 mL min−1 with a run time of 10 min. The assay was linear over a range of 0.15 μg mL−1 to 100.00 μg mL−1 with a lower limit of detection of 3.00 mg kg−1, and recoveries were greater than 90%. The intra-day and inter-day precision was less than 4%. This method was successful in determining free proline in honey, ranging from 80.5 mg kg−1 to 426.4 mg kg−1 in different honey samples.
Xue-Jiao Zhao,Na Wang,Ming-Jun Zhang,Sha-Sha Liu,Hui Yu,Mo-Huan Tang,Zhao-Ying Liu
A method for the simultaneous determination of aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), taurine (Tau) and gamma-aminobutyric acid (GABA) in animal blood and brain by two-dimensional liquid chromatography (2D-LC) combined with ultraviolet detection was established for the first time. First, the amino acid neurotransmitters (AANTs) were labeled on the corresponding fluorescent derivatives with 4-fluoro-7-nitrobenzofurazan (NBD-F), enriched on the extraction column and automatically transferred to the analytical column to achieve on-line extraction and complete separation of the target components. This method exhibited good selectivity, and the correlation coefficients for the analyte calibration curves of were > 0.99. The intra- and inter-day precisions were ≤ 16.03, and the accuracies were in the range of 70.59–116.20%. The system realizes the rapid detection and stability quantification of the five AANTs, which proves that the alternative dilution method is feasible. The results show that the system has high loading capacity, excellent resolution, and good peak shape and is not affected by other endogenous substances. Moreover, the developed method has been successfully applied to the analysis of biological samples in the blood and whole brain of rats and pigs. The content of AANTs in the hippocampus and cortex of rats was higher than that in those of pigs. This method is expected to provide applicability for the determination of AANTs in pharmacological, pharmaceutical and clinical research in nervous science.