Grupo de Investigación en Cromatografía y Técnicas Afines GICTA, Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, Manizales, Colombia.
Química de Plantas Colombianas, Instituto de Química, Escuela de Ciencias Exactas y Naturales, Universidad de Antioquia, Calle 70 No. 52-21, A.A, 1226, Medellín, Colombia.
Anal Chim Acta. 2017 Feb 8;953:23-31. doi: 10.1016/j.aca.2016.11.067. Epub 2016 Dec 3.
Montmorillonite (MMT) clays were modified by the intercalation into their galleries of ionic liquids (IL) based on imidazolium quaternary ammonium salts. This new eco-materials exhibited good features for use as a sorptive phase in the extraction of low-polarity analytes from aqueous samples. Spectroscopic analyses of the modified clays were conducted and revealed an increase in the basal spacing and a shifting of the reflection plane towards lower values as a consequence of the effective intercalation of organic cations into the MMT structure. The novel sorbent developed herein was assayed as the sorptive phase in rotating-disk sorptive extraction (RDSE), using polychlorinated biphenyls (PCBs), representative of low-polarity pollutants, as model analytes. The final determination was made by gas chromatography with electron capture detection. Among the synthetized sorptive phases, the selected system for analytical purposes consisted of MMT modified with the 1-hexadecyl-3-methylimidazolium bromide (HDMIM-Br) IL. Satisfactory analytical features were achieved using a sample volume of 5 mL: the relative recoveries from a wastewater sample were higher than 80%, the detection limits were between 3 ng L and 43 ng L, the precision (within-run precision) expressed as the relative standard deviation ranged from 2% to 24%, and the enrichment factors ranged between 18 and 28. Using RDSE, the extraction efficiency achieved for the selected MMT-HDMIM-Br phase was compared with other commercial solid phases/supports, such as polypropylene, polypropylene with 1-octanol (as a supported liquid membrane), octadecyl (C18) and octyl (C8), and showed the highest response for all the studied analytes. Under the optimized extraction conditions, this new device was applied in the analysis of the influent of a wastewater treatment plant in Santiago (Chile), demonstrating its applicability through the good recoveries and precision achieved with real samples.
蒙脱土 (MMT) 粘土通过嵌入基于季铵盐的离子液体 (IL) 而被改性。这种新型生态材料具有良好的特性，可用作从水样中提取低极性分析物的吸附相。对改性粘土进行了光谱分析，结果表明，由于有机阳离子有效嵌入到 MMT 结构中，层间距增加，反射面向低值移动。本文开发的新型吸附剂被用作旋转圆盘吸附萃取 (RDSE) 的吸附相，以多氯联苯 (PCBs) 作为低极性污染物的模型分析物。最终的测定是通过带有电子捕获检测的气相色谱法进行的。在所合成的吸附相中，选择用于分析目的的系统是用 1-十六烷基-3-甲基咪唑溴盐 (HDMIM-Br) IL 改性的 MMT。使用 5 毫升样品体积可以获得令人满意的分析特性：从废水样品中的相对回收率高于 80%，检测限在 3ng/L 和 43ng/L 之间，精密度（批内精密度）表示为相对标准偏差范围在 2%到 24%之间，富集因子在 18 和 28 之间。使用 RDSE，比较了所选 MMT-HDMIM-Br 相的萃取效率与其他商用固相/载体，如聚丙烯、带有 1-辛醇的聚丙烯（作为支撑液膜）、十八烷基 (C18) 和辛基 (C8)，结果表明所有研究的分析物都表现出最高的响应。在优化的萃取条件下，该新型装置应用于圣地亚哥（智利）污水处理厂的进水分析，通过对实际样品的良好回收率和精密度证明了其适用性。
