A novel fluorescent labeling reagent toluene-4-sulfonic acid 2-(2-thiophen-2-yl-phenanthro[9,10-d]imidazol-1-yl)-ethyl ester has been designed and synthesized. It was used to label twenty-six fatty acids (C5–C30) successfully in the presence of K₂CO₃ catalyst in N,N-dimethylformamide solvent. The reaction conditions were optimized by employing a three-factor, three-level Box–Behnken design. Derivatives were sufficiently stable to be efficiently analyzed by high-performance liquid chromatography with fluorescence detection. All fatty acid derivatives were separated on a hypersil BDS-C8 column in conjunction with a gradient elution with a good baseline resolution. Good linear correlations were observed for all fatty acids with correlation coefficients > 0.993. The established method exhibited high sensitivity and excellent repeatability. The limit of detection (at a signal-to-noise ratio of 3 : 1) was 8.8–45.5 fmol. The method was used to quantify free fatty acids in ginkgo nut and ginkgo leaf samples with satisfactory results.

中文翻译：

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甲苯-4-磺酸2-(2-噻吩-2-基-菲[9,10-d]咪唑-1-基)-乙酯的合成及其在银杏果中游离脂肪酸的灵敏测定中的应用银杏叶高效液相色谱荧光检测

设计合成了一种新型荧光标记试剂甲苯-4-磺酸2-(2-噻吩-2-基-菲[9,10- d ]咪唑-1-基)-乙酯。在N , N _ _{_ _} _-二甲基甲酰胺溶剂。通过采用三因素、三水平 Box-Behnken 设计优化反应条件。衍生物足够稳定，可以通过具有荧光检测的高效液相色谱进行有效分析。所有脂肪酸衍生物均在 hypersil BDS-C8 色谱柱上分离，并结合具有良好基线分辨率的梯度洗脱。所有脂肪酸均观察到良好的线性相关性，相关系数 > 0.993。所建立的方法具有高灵敏度和优异的重复性。检测限（信噪比为 3:1）为 8.8-45.5 fmol。采用该方法对银杏果和银杏叶样品中的游离脂肪酸进行定量，结果满意。