标题：Determination of long-chained alkylimidazolium ionic liquids based on the hypochromic effect
作者：Yu Tong;Hongxiao Yang;Yixian Huang
作者机构：[Tong, Yu] Key Laboratory for Special Functional Aggregated Materials of Education Ministry, School of Chemistry and Chemical Engineering, Shandong Un 更多
通讯作者地址：[Yang, YZ]Shandong Univ, Sch Chem & Chem Engn, Educ Minist, Key Lab Special Funct Aggregated Mat, Jinan 250100, Peoples R China.
摘要：The hypochromic effect of bromocresol green (BCG) resulted from long-chained imidazolium ionic liquids was investigated. The hypochromic effect may be caused by the formation of the neutral complex [C_nmim]2~+[BCG]~(2-) via electrostatic interaction and hydrophobic interaction. Based on the spectral characteristics, a new method for determination of long-chained imidazolium ionic liquids is developed. The proposed method can be performed using a UV-vis spectrophotometer, at the optimum λ_(min). Beer\'s law is obeyed in the concentration range of 0.004-0.04 mmol L~(-1) for [C_(14)mim]Br and [C_(16)mim]Cl, and the detection limits are 0.0011 and 0.00095 mmol L~(-1) for [C_(14)mim]Br and [C_(16)mim]Cl, respectively. Meanwhile, precision, accuracy and tolerance are also very good. The method is fast, economical and does not require organic solvents; it can be applied for determination of long-chained imidazolium ionic liquids.