Synthesis and application of imidazolium-based ionic liquids as extraction solvent for pretreatment of triazole fungicides in water samples

Abstract

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.

Cathodic Behaviour of Dicationic Imidazolium Bromides: The Role of the Spacer

“…[3] The main advantage in using DILs instead of the corresponding ILs lies in the possibility of further modulating their properties varying the nature of the spacer. [4] In fact, imidazolium DILs have been successfully used as electrolytes in dye sensitized solar cells (DSSCs), [5] as efficient replacements of organic phase-change materials (the heat capacity of DILs is noteworthy higher than that of the corresponding monocations), [6,7] as solvents for the controlled pyrolysis of cellulose, [8] as templates for the synthesis of ZnO nanostructures in water, [9,10] as surfactants (due to a better capacity of aggregation with respect to monocationic analogues), [11] as efficient extractors of phenolic compounds from oil mixtures [12] or of triazole fungicides from contaminated water, [13] etc.…”

Advances Brought by Hydrophilic Ionic Liquids in Fields Involving Pharmaceuticals

“…At this point, a hydrophobic IL capable of being dispersed through the sample is yielded, producing microdroplets where the target analytes are enriched [ 121 ]. Reports on the determination of antibiotics [ 152 ], phenolic endocrine-disrupting chemicals [ 153 , 154 ] and triazole fungicides [ 155 ] in a multitude of samples (viz., food, environmental water samples, toys, pacifiers, industrial effluents) with the aid of such an approach are available. Examples of ILs applied are mono- (e.g., [C n C 1 im]Cl/Br, [C n C 4 im]Br and [C 7 H 7 C 1 im]Cl) and dicationic (e.g., [C 4 (C n im) 2 ]Br 2 ) imidazolium-based, together with [PF 6 ] – and [NTf 2 ] – salts as the ion exchange agent [ 152 , 153 , 154 , 155 ].…”

“…Reports on the determination of antibiotics [ 152 ], phenolic endocrine-disrupting chemicals [ 153 , 154 ] and triazole fungicides [ 155 ] in a multitude of samples (viz., food, environmental water samples, toys, pacifiers, industrial effluents) with the aid of such an approach are available. Examples of ILs applied are mono- (e.g., [C n C 1 im]Cl/Br, [C n C 4 im]Br and [C 7 H 7 C 1 im]Cl) and dicationic (e.g., [C 4 (C n im) 2 ]Br 2 ) imidazolium-based, together with [PF 6 ] – and [NTf 2 ] – salts as the ion exchange agent [ 152 , 153 , 154 , 155 ]. A hydrophobic IL containing the imidazolium cation and the [PF 6 ] – or [NTf 2 ] – anions from the parent IL and the ion exchange salt, respectively, is yielded, easily dispersing through the sample with no need of an extra dispersant [ 152 , 153 , 154 , 155 ].…”

“…Examples of ILs applied are mono- (e.g., [C n C 1 im]Cl/Br, [C n C 4 im]Br and [C 7 H 7 C 1 im]Cl) and dicationic (e.g., [C 4 (C n im) 2 ]Br 2 ) imidazolium-based, together with [PF 6 ] – and [NTf 2 ] – salts as the ion exchange agent [ 152 , 153 , 154 , 155 ]. A hydrophobic IL containing the imidazolium cation and the [PF 6 ] – or [NTf 2 ] – anions from the parent IL and the ion exchange salt, respectively, is yielded, easily dispersing through the sample with no need of an extra dispersant [ 152 , 153 , 154 , 155 ]. As claimed with the extraction of tetracyclines from food samples [ 152 ], the analytical performance of in situ IL-DLLME using [C 7 H 7 C 1 im]Cl and NH 4 PF 6 (CFs = 25–98 and limits of detection = 0.12–0.45 µg/L) matched or even overwhelmed that of other previously reported methods including conventional IL-DLLME using hydrophobic ILs and SPE.…”

Probabilistic ecotoxicological risk assessment of imidazolium ionic liquids with amino acid and halide anions

“…ILs are emerging solvents and the family of ILs based on imidazolium has the potential for many industrial processes and applications [28]. A number of acute toxicity data are available for the imidazolium ILs.…”