In situ growth of zeolitic imidazolate framework-8 on a GO–PVDF membrane as a sorbent for thin-film microextraction of caffeine followed by quantitation through high-performance liquid chromatography

2020 ◽  
Vol 12 (13) ◽  
pp. 1736-1743 ◽  
Author(s):  
Zahra Jafari ◽  
Mohammad Reza Hadjmohammadi
Keyword(s):  
Thin Film ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
In Situ Growth ◽  
Zeolitic Imidazolate Framework ◽  
Pvdf Membrane

In the present study, the applicability of ZIF-8/LDH/GO/PVDF as a sorbent for the thin film microextraction (TFME) method is introduced.

scholarly journals In Situ Synthesis of a Magnetic Graphene Platform for the Extraction of Benzimidazoles from Food Samples and Analysis by High-Performance Liquid Chromatography

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Qianchun Zhang ◽  
Yulan Liu ◽  
Xingyi Wang ◽  
Huimin Li ◽  
Junyu Chen
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Magnetic Solid Phase Extraction ◽  
Food Samples ◽  
Magnetic Graphene ◽  
Relative Standard

A novel method was proposed for the determination of five benzimidazoles (oxfendazole, mebendazole, flubendazole, albendazole, and fenbendazole) using magnetic graphene (G-Fe3O4). G-Fe3O4 was synthesized via in situ chemical coprecipitation. The properties of G-Fe3O4 were characterized by various instrumental methods. G-Fe3O4 exhibited a great adsorption ability and good stability towards analytes. Various experimental parameters that might affect the extraction efficiency such as the amount of G-Fe3O4, extraction solvent, extraction time, and desorption conditions were evaluated. Under the optimized conditions, a method based on G-Fe3O4 magnetic solid-phase extraction coupled with high-performance liquid chromatography was developed. A good linear response was observed in the concentration range of 0.100–100 μg/L for the five benzimidazoles, with correlation coefficients ranging from 0.9966 to 0.9998. The limits of detection (S/N=3) of the method were between 17.2 and 32.3 ng/L. Trace benzimidazoles in chicken, chicken blood, and chicken liver samples were determined and the concentrations of oxfendazole, mebendazole, flubendazole, and fenbendazole in these samples were 13.0–20.2, 1.62–4.64, 1.94–6.42, and 0.292–1.04 ng/g, respectively. The recovery ranged from 83.0% to 115%, and the relative standard deviations were less than 7.9%. The proposed method was sensitive, reliable, and convenient for the analysis of trace benzimidazoles in food samples.

Simple in-situ growth of layered Ni 3 S 2 thin film electrode for the development of high-performance supercapacitors

2017 ◽  
Vol 399 ◽  
pp. 432-439 ◽  
Author(s):  
Fengzhen Ji ◽  
Dan Jiang ◽  
Xinman Chen ◽  
Xuexue Pan ◽  
Liping Kuang ◽  
...  
Keyword(s):  
Thin Film ◽  
High Performance ◽  
Film Electrode ◽  
In Situ Growth ◽  
Thin Film Electrode

scholarly journals Determination of Very Low Concentration of Bisphenol A in Toys and Baby Pacifiers Using Dispersive Liquid–Liquid Microextraction by In Situ Ionic Liquid Formation and High-Performance Liquid Chromatography

2020 ◽  
Vol 13 (10) ◽  
pp. 301
Author(s):  
Yesica Vicente-Martínez ◽  
Manuel Caravaca ◽  
Antonio Soto-Meca
Keyword(s):  
Ionic Liquid ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
The Body ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction ◽  
Total Extraction

Bisphenol A (BPA) is a chemical compound used in the manufacturing of plastics and resins whose presence in the body in low concentrations can cause serious health problems. Due to this, there is a growing interest in the scientific community to develop analytical methods that allow quantifying trace concentrations of BPA in different types of samples. The determination of this compound in toys made of plastics that can be manipulated by children leads to an extra concern, because it is possible for BPA to enter the body by introducing these toys into the mouth. This work presents a novel procedure to the quickly and easily quantification of trace levels of BPA in samples of toys and pacifiers according to the current demanding regulations. The determination of very low levels of BPA was carried out by ionic liquid dispersive liquid–liquid microextraction (IL-DLLME) followed by high-performance liquid chromatography (HPLC). The formation in situ of the ionic liquid (IL) 1-octyl-3-methylimidazolium bis((trifluoromethane)sulfonyl)imide ([C8MIm] [NTf2]), was achieved by mixing 1-octyl-3-methylimidazolium chloride ([C8MIm]Cl) and lithium bis(trifluoromethanesulfonyl)imide ([NTf2]Li) aqueous solutions, reaching an instant dispersion whose cloud of microdrops allows the total extraction of BPA in the IL from aqueous solutions. After centrifugation, BPA concentration in the sedimented phase was determined by HPLC. The optimal experimental conditions for the microextraction and determination of BPA in the IL were studied. The total extraction was achieved at pH 4, heating the sample at 30 °C for 5 min, using 100 µL of IL precursor volume, and spinning after the formation of dispersion at 3000 rpm for 10 min. The enrichment factor (EF) and detection limit (LOD) reached with the procedure were 299 and 0.19 µg L−1, respectively. The relative standard deviation for ten replications at the 0.5 µg L−1 level was 5.2%. Recovery studies showed a mean value for BPA recovery percentage in the samples of 99%. Additionally, a hybrid model was applied to characterize the extraction kinetics. This simple, low cost and fast method simplifies traditional microextraction techniques, representing an outstanding alternative.

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