Yang Jiale, Fan Chen, Kong Dandan, Tang Gang, Zhang Wenbing, Dong Hongqiang, Liang You, Wang Deng, Cao Yongsong
College of Plant Protection, China Agricultural University, No. 2 Yuanmingyuan West Road, Beijing, 100193, China.
Anal Bioanal Chem. 2018 Feb;410(6):1647-1656. doi: 10.1007/s00216-017-0820-x. Epub 2018 Jan 2.
Five novel ionic liquids (ILs), 1,3-dibutylimidazolium bromide [BBMIm][Br], 1-pentyl-3-butylimidazolium bromide [BPMIm][Br], 1-hexyl-3-butylimidazolium bromide [BHMIm][Br], 1,1'-(butane-1,4-diyl)bis(3-butylimidazolium) bromide [C(BMIm)][Br], and 1,1'-(butane-1,4-diyl)bis(3-methylimidazolium) bromide [C(MIm)][Br], were prepared and used in situ to react with bis(trifluoromethane)sulfonamide lithium salt to extract the myclobutanil, tebuconazole, cyproconazole, and prothioconazole from water samples. The results showed that mono-cationic ILs had much better recovery than dicationic ILs, and mono-imidazolium IL bearing butyl groups at N-1 and N-3 sites had the best recovery. When the length of the alkyl substituent group was more than four carbons at N-3 site, the recovery decreased with increase of alkyl chain length of 1-butylimidazolium IL. The extraction efficiency order of triazoles from high to low was [BBMIm][Br], [BPMIm][Br], [BHMIm][Br], [BMIm][Br] (1-butyl-3-methylimidazolium bromide), [C(BMIm)]Br, [C(MIm)]Br. An in situ ionic liquid dispersive liquid-liquid microextraction combined with ultrasmall superparamagnetic FeO was established as a pretreatment method for enrichment of triazole fungicides in water samples by using the synthetic [BBMIm][Br] as the cationic IL and used to detect analytes followed by high-performance liquid chromatography. Under the optimized conditions, the proposed method showed a good linearity within a range of 5-250 μg L, with the determination coefficient (r) varying from 0.998 to 0.999. High mean enrichment factors were achieved ranging from 187 to 323, and the recoveries of the target analytes from real water samples at spiking levels of 10.0, 20.0, and 50.0 μg L were between 70.1% and 115.0%. The limits of detection for the analytes were 0.74-1.44 μg L, and the intra-day relative standard deviations varied from 5.23% to 8.65%. The proposed method can be further applied to analyze and monitor pesticides in other related samples. Graphical Abstract The scheme of the in-situ DLLME method for the determination of triazoles using the imidazolium-based ionic liquids.
制备了五种新型离子液体（ILs），即1,3 - 二丁基咪唑溴盐[BBMIm][Br]、1 - 戊基 - 3 - 丁基咪唑溴盐[BPMIm][Br]、1 - 己基 - 3 - 丁基咪唑溴盐[BHMIm][Br]、1,1'-（丁烷 - 1,4 - 二基）双（3 - 丁基咪唑）溴盐[C(BMIm)][Br]和1,1'-（丁烷 - 1,4 - 二基）双（3 - 甲基咪唑）溴盐[C(MIm)][Br]，并使其原位与双（三氟甲烷）磺酰胺锂盐反应，用于从水样中萃取腈菌唑、戊唑醇、环丙唑醇和丙硫菌唑。结果表明，单阳离子离子液体的回收率比双阳离子离子液体好得多，且在N - 1和N - 3位带有丁基的单咪唑离子液体回收率最佳。当N - 3位烷基取代基长度超过四个碳时，1 - 丁基咪唑离子液体的回收率随烷基链长度增加而降低。三唑类的萃取效率顺序从高到低为[BBMIm][Br]、[BPMIm][Br]、[BHMIm][Br]、[BMIm][Br]（1 - 丁基 - 3 - 甲基咪唑溴盐）、[C(BMIm)]Br、[C(MIm)]Br。建立了一种原位离子液体分散液液微萃取结合超小超顺磁性FeO的方法，以合成的[BBMIm][Br]作为阳离子离子液体，用于水样中三唑类杀菌剂的富集预处理，随后用高效液相色谱法检测分析物。在优化条件下，该方法在5 - 250 μg L范围内具有良好的线性，测定系数（r）在0.998至0.999之间。实现了187至323的高平均富集因子，在10.0、20.0和50.0 μg L加标水平下，实际水样中目标分析物的回收率在70.1%至115.0%之间。分析物的检测限为0.74 - 1.44 μg L，日内相对标准偏差在5.23%至8.65%之间。该方法可进一步应用于分析和监测其他相关样品中的农药。图形摘要 使用咪唑基离子液体测定三唑类的原位分散液液微萃取方法示意图
