[MeCl4]-型配阴离子-亚甲蓝离子缔合物的溶剂萃取和荧光法测定痕量亚甲蓝  

Determination of Trace Amount Methylene Blue Based on [MeCl_4]^--MB Ionic Associate by Solvent Extraction-fluorophotometry

作　　者：杨季冬[1] 石文兵[2] 刘绍璞[1] 

机构地区：[1]西南大学化学化工学院,重庆400715 [2]长江师范学院化学及环境科学系,重庆408003

出　　处：《高等学校化学学报》2008年第4期720-725,共6页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20475045);重庆市教委科技研究项目基金(批准号:KJ051303)资助

摘　　要：研究了离子缔合物溶剂萃取的适宜条件、有机相中荧光和共振荧光光谱特征,讨论了离子缔合物的组成和结构,考察了有关的分析化学性质.建立了测定痕量亚甲蓝的高灵敏度的方法,其检出限分别为0.2和0.6ng/mL(荧光法)以及1.1和2.8ng/mL(共振荧光法),荧光法具有更高的灵敏度,更宜于痕量亚甲蓝的测定.将该方法用于人血清和尿样中痕量亚甲蓝的测定,结果较好.Abstract In HCl medium, AuCl4ˉ and GaCl4ˉ could react with methylene blue（MB） to form two ionic associates, which could he easily extracted by 1,2-dichloromethane solvent and resulted in the fluorescence enhanced significantly in organic phase. Their maximum excitation wavelengths （λex） located at 656 and 666 nm, respectively ; and their maximum emission wavelengths （ λem） were 674 and 685 nm, respectively. The synchronized fluorescence spectra（△λ =0） could he recorded with synchronous scanning at λex = λem, and it could he proved by the fluorescence polarization experiment that they were resonance fluorescence. The resonance fluorescence peaks of two ionic associates located at 660 and 671 nm, respectively, which was found in the intersection of excitation spectra and the emission spectra. Both intensities（AF） of fluorescence and resonance fluorescence were directly proportional to the concentration of MB in a certain ranges, so the high sensitivity methods of determination of trace amount MB were established, and their detection limits （3σ） were 0. 2 and 0. 6 ng/mL for fluoresence method, as well as 1.1 and 2.8 ng/mL for resonance fluoresence method, respectively. The fluorescence method has a higher sensitivity and is more suitable in determination of trace amount MB. In the paper, the optimum conditions for organic solvent extration, the spectra characteristics of fluorescence and resonance fluorescence were discussed. Besides, the composition and structure of [ MeCl4 ]ˉ-MB ionic associates were studied. The fluorescence method could he applied to the determination of MB in urine samples and human serum samples with satisfactory results.

关 键 词：亚甲蓝 溶剂萃取 离子缔合物 共振荧光 

分 类 号：O657[理学—分析化学]