荧光衍生试剂1-［2-(对甲苯磺酸酯)乙基］-2-苯基咪唑［4,5-f］9,10-菲的合成及其在长链脂肪酸分析中的应用

合成了新的荧光衍生试剂1-［2-(对甲苯磺酸酯)乙基］-2-苯基咪唑［4,5-f］9,10-菲(TSEPIP),并将其作为柱前衍生化试剂,在Eclipse XDB-C8色谱柱上采用梯度洗脱实现了11种长链(C20~C30)游离脂肪酸(FFA)衍生物的基线分离。利用柱后在线的串联质谱并以大气压化学电离源（APCI）的正离子模式实现了各组分的质谱定性。对土壤及3种苔藓(东亚毛灰藓、锦丝藓、羽平藓)中FFA组分的定量结果表明,苔藓植物从土壤中富集了大量的长链游离脂肪酸。荧光检测的激发波长和发射波长分别为260 nm和380 nm。线性回归系数大于0.9996,检测限为26.19~76.67 fmol。所建立的方法具有良好的重现性,对实际样品的测定结果令人满意。

Synthesis of 1-[2-(p-Toluenesulfonate)Ethyl]-2-Phenylimidazole [4,5-f] 9,10-Phenanthrene and Its Application for Analysis of Long-Chain Fatty Acids

A simple and sensitive method for the determination of long-chain free fatty acids (FFAs) using 1-2-(p-toluenesulfonate) ethyl]-2-phenylimidazole 4, 5-f] 9, 10-phenanthrene (TSEPIP) as pre-column derivatization reagent by reversed-phase high performance liquid chromatography with fluorescence detection and mass spectrometric identification was developed. Eleven long-chain (C20-C30) FFA derivatives were separated on Eclipse XDB-C8 column with a good baseline resolution. Studies on derivatization conditions indicate that FFA reacts rapidly and smoothly with TSEPIP in the presence of K2CO3, catalyst at 90 degrees C in N, N-dimethylformamide solvent to give the corresponding sensitively fluorescent derivatives with maximal yields close to 100% with a 5-fold molar reagent excess. The identification of 11 FFA derivatives was carried out by online post-column mass spectrometry with atmospheric pressure chemical ionization source in positive-ion mode. The contents of 11 FFAs in soil and three bryophytes (Homomallium connexum (Card.) Broth., Actinothuidium hookeri, Neckera pennata) were determined. The results indicate that the bryophyte plants enrich an abundance of FFAs from soil. The excitation and emission wavelengths of fluorescence detection were set at 260 nm and 380 nm, respectively. Linear correlation coefficients for the most FFA derivatives were higher than 0.9996, and the detection limits (at signal-to-noise of 3:1) were 26.19-76.67 fmol. The method is sensitive and reproducible for the determination of long-chain FFAs in real samples.