离子液体[MBPy]Tf2N的光谱特征及荧光法检测

Spectral Performance and Fluorescence Detection of Ionic Liquid [MBPy]Tf_2N

为满足疏水性离子液体N-甲基-N-丁基吡咯烷双三氟甲烷磺酰亚胺盐（[MBPy]Tf2N）在甘草酸生物催化体系中分析检测的需要,研究了[MBPy]Tf2N的光谱特征,并考察了溶剂、醇-水混合溶剂和p H值对[MBPy]Tf2N荧光特性的影响,建立了生物催化体系中[MBPy]Tf2N的荧光光谱检测方法.研究结果表明,[MBPy]Tf2N在186 nm处有1个最大吸收峰,常规紫外检测法不适于对其进行检测;[MBPy]Tf2N荧光光谱最大激发波长为228 nm,发射波长为340 nm,且其耐光褪色性良好,在水溶液中荧光量子产率为0.067,在醇-水混合溶剂中其荧光强度有增大趋势,在碱性介质中其荧光强度受影响较大;荧光光谱法检测[MBPy]Tf2N的检出限（S/N=3）为1.00μg/m L,标准曲线在5.00-1.25×10^3μg/m L浓度范围内线性关系良好（R2=0.9999）,生物反应液中加标回收率为97.4%-107.4%（相对标准偏差RSD=4.6%）.

The detection method of hydrophobic ionic liquid N-methyl-N-butyl pyrrolidinium bis[（ trifluoromethyl） sulfonyl]imide（ [MBPy]Tf2N） was established by means of fluorescence spectrum and applied for the analysis of [MBPy]Tf2N from glycyrrhizin biological catalysis system containing ionic liquid. The effects of solvent,ethanol-water mixture solvent and p H on fluorescence spectrum were explored. Spectral features of[MBPy]Tf2N,the maximum absorption wavelength at 186 nm,were apparently cannot detect [MBPy]Tf2N by common UV method. The maximum excitation wavelength of [MBPy]Tf2N is at 228 nm and the maximum emission wavelength of it is at 340 nm,which can well againsted photobleaching and the fluorescence quantum yield was 0. 067 in water. The fluorescence intensity increased in ethanol-water mixture solvent and changed much in alkaline medium. The fluorescence detection method for [MBPy]Tf2N had a wide linear range over[MBPy]Tf2N concentration from 5.00 to 1. 25 × 10^3μg /m L with a detection limit of 1.00 μg /m L（ S /N = 3）.The spiked recoveries were from 97.4% to 107.4%（ RSD = 4.6%） in glycyrrhizin biological catalysis system.