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

Determination of Azole Fungicide Residues in Fresh Juice by Magnetic Solid Phase Extraction Based on Fe3O4@ZnAl-LDH@MIL-53(Al) Sorbent in Combination with High-Performance Liquid Chromatograph

In this work, a magnetic adsorption material based on metal-organic framework (Fe3O4@ZnAl-LDH@MIL-53(Al)) was synthesized and used as an adsorbent in the process of magnetic solid phase extraction. Then, a high-performance liquid chromatograph was used to quantitatively detect triazole fungicides in samples. In order to verify the successful preparation of the material, a series of characterization analyses were carried out. Besides, the key parameters that may affect the extraction efficiency have been optimized, and under optimal conditions the three triazole fungicides showed good linearity in the range of 10-1000 μg/L (R2 ≥ 0.9796); Limit of detections were ranged from 0.013 to 0.030 μg/mL. Finally, the established method was applied to the detection of triazole fungicides in four fresh juice samples. The results showed that the target analyte was not detected in all the test samples. By detecting the recoveries (73.3-104.3%) and coefficient variation (RSD ≤ 6.8%) of triazole fungicides in fortified samples, it proved that this established method meets the requirements of pesticide residue analysis and showed excellent application potential.

Construction of a magnetic solid-phase extraction method for the analysis of azole pesticides residue in medicinal plants

In this work, a sensitive and cost-effective method for the quantitative analysis of azole pesticides residues in six medicinal plants was established based on magnetic cyclodextrin crosslinked with tetrafluoroterephthalonitrile (Fe₃O₄@TFN-CDPs) coupled with high-performance liquid chromatography (HPLC). Through characterization analysis, the outer shell of Fe₃O₄@TFN-CDPs has observed coating with a network of the polymer and forming a core-shell structure. Under the optimum conditions, the limits of detection (LODs) and limits of qualification (LOQs) of target pesticides were ranged from 0.011 to 0.106 µg Kg^-1 and from 0.036 to 0.354 µg Kg^-1, respectively. Finally, the achieved recoveries of pesticides in six medicinal samples fluctuated from 60.1% to 102.3%. Altogether, this method based on Fe₃O₄@TFN-CDPs composites provided a new idea for the analysis of trace pesticides in complicated matrices.

Surface properties of dicationic ionic liquids and correlation with biological activity

The surface activity of dicationic ionic liquids is described in this paper. The basic interfacial parameters including critical micelle concentration (CMC), surface tension at the CMC (γ CMC), the adsorption efficiency (pC20), surface excess (Γmax), the minimum surface occupied by a single molecule (A min), and Gibbs energy (ΔG 0 ads) were investigated and compared. Basically, we wanted to extend our previous study on dicationic ionic liquids with bis-ammonium cation. Knowing that, the compounds obtained are effective in limiting the feeding of adult and larvae confused flour beetle (T. confusum), it was decided to correlate the deterrent activity with the surface properties of analyzed dicationic ionic liquids. Accordingly, it was found that the deterrent activity of the studied compounds increases with increasing wetting ability.

Sample preparation techniques for suspect and non-target screening of emerging contaminants

The progress in sensitivity and resolution in mass spectrometers in recent years provides the possibility to detect a broad range of organic compounds in a single procedure. For this reason, suspect and non-target screening techniques are gaining attention since they enable the detection of hundreds of known and unknown emerging contaminants in various matrices of environmental, food and human sources. Sample preparation is a critical step before analysis as it can significantly affect selectivity, sensitivity and reproducibility. The lack of generic sample preparation protocols is obvious in this fast-growing analytical field, and most studies use those of traditional targeted analysis methods. Among them, solvent extraction and solid phase extraction (SPE) are widely used to extract emerging contaminants from solid and liquid sample types, respectively. Sequential solvent extraction and a combination of different SPE sorbents can cover a broad range of chemicals in the samples. Gel permeation chromatography (GPC) and adsorption chromatography, including acidification, are typically used to remove matrix components such as lipids from complex matrices, but usually at the expense of compound losses. Ideally, the purification of samples intended for non-target analysis should be selective of matrix interferences. Recent studies have suggested quality assurance/quality control measures for suspect and non-target screening, based on expansion and extrapolation of target compound lists, but method validations remain challenging in the absence of analytical standards and harmonized sample preparation approaches.

Advances Brought by Hydrophilic Ionic Liquids in Fields Involving Pharmaceuticals

The negligible volatility and high tunable nature of ionic liquids (ILs) have been the main drivers of their investigation in a wide diversity of fields, among which is their application in areas involving pharmaceuticals. Although most literature dealing with ILs is still majorly devoted to hydrophobic ILs, evidence on the potential of hydrophilic ILs have been increasingly provided in the past decade, viz., ILs with improved therapeutic efficiency and bioavailability, ILs with the ability to increase drugs' aqueous solubility, ILs with enhanced extraction performance for pharmaceuticals when employed in biphasic systems and other techniques, and ILs displaying low eco/cyto/toxicity and beneficial biological activities. Given their relevance, it is here overviewed the applications of hydrophilic ILs in fields involving pharmaceuticals, particularly focusing on achievements and advances witnessed during the last decade. The application of hydrophilic ILs within fields involving pharmaceuticals is here critically discussed according to four categories: (i) to improve pharmaceuticals solubility, envisioning improved bioavailability; (ii) as IL-based drug delivery systems; (iii) as pretreatment techniques to improve analytical methods performance dealing with pharmaceuticals, and (iv) in the recovery and purification of pharmaceuticals using IL-based systems. Key factors in the selection of appropriate ILs are identified. Insights and perspectives to bring renewed and effective solutions involving ILs able to compete with current commercial technologies are finally provided.

Popping candy-assisted dispersive liquid-liquid microextraction for enantioselective determination of prothioconazole and its chiral metabolite in water, beer, Baijiu, and vinegar samples by HPLC

To simultaneously determine the enantiomers of prothioconazole and its chiral metabolite prothioconazole-desthio in water, beer, Baijiu, and vinegar samples by HPLC, a simple, fast, environmentally-friendly popping candy-assisted dispersive liquid-liquid microextraction technique was developed. A green medium-chain fatty acid (decanoic acid) and popping candy could be used as the extractant and solid dispersant respectively to avoid the use of toxic organic solvents. Decanoic acid was collected after extraction by solidification at room temperature. The linear range of this technique was from 27.1 to 1000 µg L^-1. The limits of detection and quantification were within the ranges of 8.1-11.2 μg L^-1 and 27.1-37.3 μg L^-1, respectively. The extraction recovery was 80.8% to 102.5% with the relative standard deviation ranged from 1.1 to 7.1%. This technique has been successfully applied to enantioselectively determine the residues of prothioconazole and prothioconazole-desthio in water, beer, Baijiu, and vinegar samples.

Magnetic solid-phase extraction based on nano-zeolite imidazolate framework-8-functionalized magnetic graphene oxide for the quantification of residual fungicides in water, honey and fruit juices

In this work, zeolite imidazolate framework-8 (ZIF-8) functionalized magnetic graphene oxide (Fe3O4@APTES-GO/ZIF-8) was successfully synthesized and used as a novel adsorbent in magnetic solid-phase extraction (MSPE) for the determination of four triazole fungicides in water, honey and fruit juices. The main parameters such as extraction time, amount of adsorbent, the pH value of the sample, ionic strength, and desorption solvent which could affect the experiment results were optimization. Under the optimum condition, the obtained linearity of this method ranged from 1 to 1000 µg L-1 for all analytes, with correlation coefficients (R2) ≥ 0.9914. Limit of detections (LODs) and limit of qualifications (LOQs) of four triazole fungicides were ranged from 0.014 to 0.109 µg L-1 and from 0.047 to 0.365 µg L-1, respectively. Based on comparison with outcomes from other studies, Fe3O4@APTES-GO/ZIF-8-MSPE could provide high performance and achieve satisfied results for the analysis of trace triazole fungicides in complicated matrices.

Relationship between the Structure of Ionic Liquid and Its Enrichment Ability To Trace Fungicides from an Environmental Water Sample

To elucidate the relationship between the structure of ionic liquid (IL) and its enrichment ability to trace pesticides from an environmental water sample, a series of imidazole-based ILs were synthesized to extract four fungicides (boscalid, cyprodinil, fluazinam, and pyrimethanil) through an in situ ionic liquid dispersive liquid-liquid microextraction method. The results showed that aromatic heterocyclic monocation ionic liquids (MILs) had better extraction ability to fungicides than other three alicyclic heterocyclic MILs. Dication ionic liquids (DILs) with the four carbons at the side chain had better ability to extract fungicides than MILs, and DILs with a long bridge carbon chain had better recoveries of fungicides with low K_ow values. The proposed method showed high mean enrichment factors and high recoveries of the fungicides from real water samples. The rules of the relationship between the structure of IL and enrichment ability are instructive to the application of ILs in pretreatment of complex substances.