Ionic-liquid-based dispersive liquid-liquid microextraction combined with magnetic solid-phase extraction for the determination of aflatoxins B1, B2, G1, and G2in animal feeds by high-performance liquid chromatography with fluorescence detection

An analytical method has been developed for the detection of a metabolite of nifursol, 3,5-dinitrosalicylic acid hydrazide, in foodstuffs of animal origin (chicken liver, pork liver, lobster, shrimp, eel, sausage, and honey). The method combines liquid chromatography and tandem mass spectrometry with liquid-liquid extraction. Samples were hydrolyzed with hydrochloric acid and derivatized with 2-nitrobenzaldehyde at 37°C for 16 h. The solutions of derivatives were adjusted to pH 7.0-7.5, and the metabolite was extracted with ethyl acetate. 3,5-Dinitrosalicylic acid hydrazide determination was performed in the negative electrospray ionization method. Both isotope-labeled internal standard and matrix-matched calibration solutions were used to correct the matrix effects. Limits of quantification were 0.5 μg/kg for all samples. The average recoveries, measured at three concentration levels (0.5, 2.0, and 10 μg/kg) were in the range of 75.8-108.4% with relative standard deviations below 9.8%. The developed method exhibits a high sensitivity and selectivity for the routine determination and confirmation of the presence of a metabolite of nifursol in foodstuffs of animal origin.

“…Sample purification methods included LLE [30][31][32][33], and SPE [34][35][36][37]. Considering that SPE is more expensive than LLE, we used LLE for sample purification.…”

Section: Optimization Of the Sample Treatment Proceduresmentioning

confidence: 99%

Determination of a metabolite of nifursol in foodstuffs of animal origin by liquid–liquid extraction and liquid chromatography with tandem mass spectrometry

Wang

Liu

et al. 2017

“…DLLME was introduced by Rezaee et al. and has been applied to extract analytes from various matrixes . DLLME has appeared in different modes, such as vortex‐assisted dispersive liquid–liquid microextraction (VA‐DLLME) , ultrasound‐assisted dispersive liquid–liquid microextraction (USA‐DLLME) and SFODME .…”

Section: Introductionmentioning

confidence: 99%

“…Among them, DLLME has proven one of the most versatile preconcentration methods to extract trace analytes from water samples. DLLME was introduced by Rezaee et al and has been applied to extract analytes from various matrixes [7][8][9][10][11][12][13][14][15]. DLLME has appeared in different modes, such as vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) [8], ultrasound-assisted dispersive liquidliquid microextraction (USA-DLLME) [9] and SFODME [10,11].…”

Section: Introductionmentioning

confidence: 99%

Air‐assisted dispersive liquid–liquid microextraction based on a new hydrophobic deep eutectic solvent for the preconcentration of benzophenone‐type UV filters from aqueous samples

Zhang

Dai

et al. 2018

102

Deep eutectic solvents are considered as new and green solvents that can be widely used in analytical chemistry such as microextraction. In the present work, a new dl-menthol-based hydrophobic deep eutectic solvent was synthesized and used as extraction solvents in an air-assisted dispersive liquid-liquid microextraction method for preconcentration and extraction of benzophenone-type UV filters from aqueous samples followed by high-performance liquid chromatography with diode array detection. In an experiment, the deep eutectic solvent formed by dl-menthol and decanoic acid was added to an aqueous solution containing the UV filters, and then the mixture was sucked up and injected five times by using a glass syringe, and a cloudy state was achieved. After extraction, the solution was centrifuged and the upper phase was subjected to high-performance liquid chromatography for analysis. Various parameters such as the type and volume of the deep eutectic solvent, number of pulling, and pushing cycles, solution pH and salt concentration were investigated and optimized. Under the optimum conditions, the developed method exhibited low limits of detection and limits of quantitation, good linearity, and precision. Finally, the proposed method was successfully applied to determine the benzophenone-type filters in environmental water samples with relative recoveries of 88.8-105.9%.

“…Due to their unique properties, their use has attracted considerable interest, including an increasing number of publications on their use in preparing stationary phases of HPLC . An active research is found in many reports on the role of ILs to modify the retention of different types of solutes in LC . Based on their UV absorption, imidazolium ILs have been applied as background reagents for determination of IL cations in the HPLC and IC with UV indirect detection.…”

Section: Introductionmentioning

confidence: 99%

Indirect ultraviolet detection of alkaline earth metal ions using an imidazolium ionic liquid as an ultraviolet absorption reagent in ion chromatography

Liu

2017

A convenient and versatile method was developed for the separation and detection of alkaline earth metal ions by ion chromatography with indirect UV detection. The chromatographic separation of Mg , Ca , and Sr was performed on a carboxylic acid base cation exchange column using imidazolium ionic liquid/acid as the mobile phase, in which the imidazolium ionic liquid acted as an UV-absorption reagent. The effects of imidazolium ionic liquids, detection wavelength, acids in the mobile phase, and column temperature on the retention of Mg , Ca , and Sr were investigated. The main factors influencing the separation and detection were the background UV absorption reagent and the concentration of hydrogen ion in ion chromatography with indirect UV detection. The successful separation and detection of Mg , Ca , and Sr within 14 min were achieved using the selected chromatographic conditions, and the detection limits (S/N = 3) were 0.06, 0.12, and 0.23 mg/L, respectively. A new separation and detection method of alkaline earth metal ions by ion chromatography with indirect UV detection was developed, and the application range of ionic liquids was expanded.