朱宜昌 施文童 宋睿

摘      要：为了认识氯化钙水溶液的核磁共振特性，探索核磁共振技术测量氯化钙水溶液浓度的新方法，配制了浓度在0%～40%范围内的氯化钙水溶液，采用CPMG自旋回波法测量了核磁共振T2谱，分析了氯化钙水溶液浓度与核磁共振横向弛豫时间及峰面积之间的函数关系，探索了通过横向弛豫时间和峰面积两种方法测量氯化钙水溶液浓度的可行性。实验结果表明：随着氯化钙水溶液浓度的增加，横向弛豫时间呈二次函数关系减小，单位质量的峰面积呈线性关系减小;与配制浓度相比，弛豫时间测量方法的相对误差均低于0.5%，峰面积测量方法的相对误差不大于2.2%;在测量的重复性上，测量数据的实验标准偏差均波动未超过测量数据均值上下2.0%的范围。

关  键  词：氯化钙水溶液;浓度;核磁共振;横向弛豫时间;峰面积

中图分类号：TE622.14         文献标识码： A     文章编号： 1671-0460（2020）05-0806-05

Abstract：  In order to understand the NMR characteristics of calcium chloride aqueous solution and explore a new method for determining the concentration of calcium chloride by NMR， the calcium chloride aqueous solution with the concentration of 0%～40%， was prepared. The NMR T2 spectrum was determined by CPMG spin-echo method， and the relationship between calcium chloride aqueous solution concentration and the transverse relaxation time and the peak area of NMR was analyzed. The experimental results showed that the transverse relaxation time decreased quadratically with the increase of the concentration of calcium chloride solution， and the peak area per unit mass decreased linearly with the increase of the concentration of calcium chloride solution. These two relationships can be used to determine the concentration of calcium chloride solution by NMR method. The relative error of relaxation time measurement method was less than 0.5%， and the relative error of peak area measurement method was not more than 2.2%.Aiming at the repeatability of measurement， the experimental standard deviation of data was less than 2.0% compared with the mean value.

Key words： Calcium chloride aqueous solution; Concentration; Nuclear magnetic resonance; Transverse relaxation time; Peak area

氯化鈣水溶液在工业生产、医学和生物学等多个方面均有重要的应用价值。高浓度氯化钙水溶液极适宜制造粒状、片状的适用于工业生产的氯化钙[1];氯化钙水溶液常常作为淬火介质被使用，可以很大程度上减少工件的变形和开裂[2，3]，氯化钙处理金属加工液还可有效去除污染且效率高[4]。氯化钙水溶液具有防冻功效及杀菌能力，可以使用氯化钙水溶液控制消毒液的凝冻温度[5]，并且热水浸泡和氯化钙处理已被用于控制番木瓜采后病害[6]。因此，氯化钙水溶液在各个领域都有着广泛的应用，但应用效果与氯化钙水溶液的浓度密切相关[1-6]。……