Department of Chemistry, Iowa State University, Ames, IA 50011, United States.
Restek Corporation, 110 Benner Circle, Bellefonte, Pennsylvania 16823, United States.
J Chromatogr A. 2023 Sep 13;1706:464222. doi: 10.1016/j.chroma.2023.464222. Epub 2023 Jul 19.
To understand factors that drive pesticide-cannabinoid selectivity in solid-phase microextraction (SPME), eight new polymeric ionic liquid (PIL) sorbent coatings were designed and compared to four previously reported PIL sorbent coatings for the extraction of pesticides. The four PIL sorbent coatings consisted of either vinylimidazolium or vinylbenzylimidazolium ILs with long alkyl chain substituents (i.e., -CH or -CH) and bis[(trifluoromethyl)sulfonyl]imide ([NTf]) anions, from which the eight new PIL sorbent coatings were adapted. Modifications to the chemical structure of IL monomers and crosslinkers included incorporation of polymerizable p-styrenesulfonate or 3-sulfopropyl acrylate anions, the addition of aromatic moieties, and/or the addition of polar functional groups (i.e., -OH or -O- groups). A total of ten commonly regulated pesticides and six cannabinoids were examined in this study. The effect of salt on the solubility of pesticides and cannabinoids in aqueous solutions was assessed by determining their extraction efficiencies in the presence of varied methanol content. Differences in their solubilities appear to play a dominant role in enhancing pesticide-cannabinoid selectivity. The selectivity, represented as the ratio of pesticide total peak areas to cannabinoid total peak areas, also exhibited a moderate correlation to the affinity of the sorbent coatings towards both the pesticides and the cannabinoids. A positive correlation was observed for the pesticides and a negative correlation was observed for the cannabinoids, suggesting that selectivity was driven by more than the presence of salt in the samples. The sorbent coatings' affinity towards each class of analytes were examined to determine specific interactions that might influence selectivity. The two main structural modifications increasing pesticide-cannabinoid selectivity included the absence of aromatic moieties and the addition of hydrogen bond donor functional groups. Extractions of simple aromatic molecules as probes were performed under similar extraction conditions as the cannabinoids and confirmed the influence of hydrogen bonding interactions on sorbent coating affinity.
为了理解固相微萃取（SPME）中农药与大麻素选择性的驱动因素，设计了 8 种新型聚合离子液体（PIL）固定相涂层，并与之前报道的 4 种 PIL 固定相涂层进行了比较，用于提取农药。这 4 种 PIL 固定相涂层由带有长烷基链取代基（即-CH 或 -CH ）和双[三氟甲基]磺酰亚胺（[NTf]）阴离子的乙烯基咪唑或乙烯基苄基咪唑 IL 组成，其中 8 种新型 PIL 固定相涂层是在此基础上进行了改进。IL 单体和交联剂的化学结构修饰包括引入可聚合的对苯乙烯磺酸盐或 3-磺丙基丙烯酸盐阴离子、添加芳基部分和/或添加极性官能团（即-OH 或-O-基团）。在这项研究中，共考察了 10 种常见的受管制农药和 6 种大麻素。通过测定它们在不同甲醇含量存在下的萃取效率，评估了盐对农药和大麻素在水溶液中溶解度的影响。溶解度的差异似乎在增强农药-大麻素选择性方面起着主导作用。用农药总峰面积与大麻素总峰面积的比值表示选择性，它与固定相涂层对农药和大麻素的亲和力也有一定的相关性。对农药呈正相关，对大麻素呈负相关，这表明选择性不仅仅是由样品中盐的存在所驱动。还考察了固定相涂层对每一类分析物的亲和力，以确定可能影响选择性的特定相互作用。增加农药-大麻素选择性的两个主要结构修饰包括去除芳基部分和添加氢键供体官能团。在与大麻素类似的萃取条件下，对简单芳香族分子作为探针进行了萃取，证实了氢键相互作用对固定相涂层亲和力的影响。
