scholarly journals Chiral Nano-Liquid Chromatography and Dispersive Liquid-Liquid Microextraction Applied to the Analysis of Antifungal Drugs in Milk

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7094
Author(s):  
Chiara Dal Bosco ◽  
Flavia Bonoli ◽  
Alessandra Gentili ◽  
Chiara Fanali ◽  
Giovanni D’Orazio
Keyword(s):  
Chiral Separation ◽  
Mobile Phase ◽  
Fused Silica ◽  
Antifungal Drugs ◽  
Experimental Conditions ◽  
Content Type ◽  
Fused Silica Capillary ◽  
Dispersive Liquid Liquid Microextraction ◽  
Slurry Packing ◽  
Liquid Microextraction

A novel chromatographic application in chiral separation by using the nano-LC technique is here reported. The chiral recognition of 12 antifungal drugs was obtained through a 75 µm I.D. fused-silica capillary, which was packed with a CSP-cellulose 3,5-dichlorophenylcarbamate (CDCPC), by means of a lab-made slurry packing procedure. The mobile phase composition and the experimental conditions were optimized in order to find the optimum chiral separation for some selected racemic mixtures of imidazole and triazole derivatives. Some important parameters, such as retention faction, enantioresolution, peak efficiency, and peak shape, were investigated as a function of the mobile phase (pH, water content, type and concentration of both the buffer and the organic modifier, and solvent dilution composition). Within one run lasting 25 min, at a flow rate of approximately 400 nL min−1, eight couples of enantiomers were baseline-resolved and four of them were separated in less than 25 min. The method was then applied to milk samples, which were pretreated using a classical dispersive liquid–liquid microextraction technique preceded by protein precipitation. Finally, the DLLME-nano-LC–UV method was validated in a matrix following the main FDA guidelines for bioanalytical methods.

Dispersive liquid–liquid microextraction followed by green high-performance liquid chromatography for fluconazole determination in cerebrospinal fluid with the aid of chemometric tools

2020 ◽  
Vol 12 (24) ◽  
pp. 3106-3114
Author(s):  
Bruna Juliana Moreira ◽  
Letícia Aparecida Schiave ◽  
Roberto Martinez ◽  
Samuel Generoso Dias ◽  
Cristiane Masetto de Gaitani
Keyword(s):  
Cerebrospinal Fluid ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
New Method ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction ◽  
Chemometric Tools

A new method, simple and fast, for fluconazole (FLU) quantification in cerebrospinal fluid (CSF) samples using dispersive liquid–liquid microextraction (DLLME) and an eco-friendly mobile phase for HPLC-PDA was developed.

scholarly journals Use of Dispersive Liquid-Liquid Microextraction and UV-Vis Spectrophotometry for the Determination of Cadmium in Water Samples

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
J. Pérez-Outeiral ◽  
E. Millán ◽  
R. Garcia-Arrona
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Experimental Conditions ◽  
Cadmium Determination ◽  
A Value ◽  
Relative Standard ◽  
Potential Applicability ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A simple and inexpensive method for cadmium determination in water using dispersive liquid-liquid microextraction and ultraviolet-visible spectrophotometry was developed. In order to obtain the best experimental conditions, experimental design was applied. Calibration was made in the range of 10–100 μg/L, obtaining good linearity (R2 = 0.9947). The obtained limit of detection based on calibration curve was 8.5 μg/L. Intra- and interday repeatability were checked at two levels, obtaining relative standard deviation values from 9.0 to 13.3%. The enrichment factor had a value of 73. Metal interferences were also checked and tolerable limits were evaluated. Finally, the method was applied to cadmium determination in real spiked water samples. Therefore, the method showed potential applicability for cadmium determination in highly contaminated liquid samples.

Fast determination of five chiral antipsychotic drugs using dispersive liquid–liquid microextraction combined with capillary electrophoresis

2020 ◽  
Vol 12 (15) ◽  
pp. 2002-2008
Author(s):  
Ming-Mu Hsieh ◽  
Tai-Chia Chiu ◽  
Szu-Hua Chen
Keyword(s):  
Capillary Electrophoresis ◽  
Chiral Separation ◽  
Antipsychotic Drugs ◽  
New Method ◽  
Fast Determination ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Phenothiazine Drugs ◽  
Liquid Microextraction

This study developed a new method for the extraction, clean up, chiral separation, and determination of five pairs of phenothiazine drugs using ultrasound-assisted dispersive liquid–liquid microextraction combined with capillary electrophoresis.

Optimized Dispersive Liquid–Liquid Microextraction Method and High Performance Liquid Chromatography with Ultraviolet Detection for Simultaneous Determination of Sorbic and Benzoic Acids and Evaluation of Contamination of These Preservatives in Iranian Foods

2015 ◽  
Vol 98 (4) ◽  
pp. 962-970 ◽  
Author(s):  
Fardin Javanmardi ◽  
Seyyed Rafie Arefhosseini ◽  
Masood Ansarin ◽  
Mahboob Nemati
Keyword(s):  
Benzoic Acid ◽  
High Performance ◽  
Fruit Juice ◽  
Experimental Conditions ◽  
Ph Optimum ◽  
Extraction Solvent ◽  
Tomato Paste ◽  
Solvent Type ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Abstract A rapid, simple, and sensitive dispersive liquid–liquid microextraction procedure followed by HPLC-UV was applied to determine the benzoate and sorbate in foods. The method was optimized for some variables including extraction solvent type and volume, dispersing solvent type and volume, and the effects of salt and pH. Optimum conditions were determined as follows: sample volume, 5 mL; extraction solvent (chloroform) volume, 250 μL; disperser solvent (acetone) volume, 1.2 mL; NaCl amount, 0.75 g/5 mL at pH 4. Sixty samples were analyzed, including 15 doogh, 15 fruit juice, 15 cookie, and 15 tomato paste; benzoic acid was detected in 57 samples (95%) at levels up to 448.1 μg/mL and sorbic acid in 31 samples (51.6%) at levels up to 1369 μg/mL. Under the optimum experimental conditions, the LOD and LOQ were determined as 0.1 and 0.5 μg/mL for benzoate and 0.08 and 0.3 μg/mL for sorbate, respectively. The results showed that these preservatives are commonly used at high levels in yogurt drinks (dooghs) and cookies. Also, the concentration of benzoic acid that was detected in the tomato paste and fruit juice samples was low but may affect children and sensitive persons.

Pre-concentration and determination of fluorescence quenching of CdS quantum dots of Pb ions by dispersive liquid–liquid microextraction in the presence of the ionic liquids

2018 ◽  
Vol 47 (2) ◽  
pp. 127-132
Author(s):  
Ehsan Jafarnejad ◽  
Jafar Abolhasani ◽  
Arezoo Derakhshan
Keyword(s):  
Quantum Dots ◽  
Ionic Liquids ◽  
Fluorescence Quenching ◽  
Cadmium Sulphide ◽  
Content Type ◽  
Relative Standard ◽  
Pb Ions ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Purpose This study aims to develop a new simple and sensitive method for the microextraction of trace levels of lead in environmental samples. It is based on the use of ionic liquids based dispersive liquid–liquid microextraction (IL–DLLME) before spectrofluorometry. Design/methodology/approach Cadmium sulphide quantum dots have been synthesised using thioglycolic acid as capping agent through a one-step process with stability and excellent water-solubility, and have strong affinity for lead (Pb). This probe is based on the fluorescence quenching effect of functionalised cadmium sulphide quantum dots. Findings Factors affecting the extraction efficiency and fluorescence quenching of metals, such as the amount of ionic liquid, amount of metanol, microextraction and centrifugation time, volume of quantum dots and buffer pH, were investigated. Under optimum conditions, the calibration graph was linear in the range of 0.01-3 µg.L-1, with the detection limit of 0.004 µg.L-1 for Pb2+. The relative standard deviation (RSD%, n = 5) of 5.4 per cent at 1 µg.L-1 of Pb2+ was obtained. Originality/value This method for pre-concentration of the Pb ions by dispersive liquid–liquid microextraction is novel and could be used for various applications in the synthesis of a wide variety of determination of fluorescence quenching of cadmium sulphide quantum dots.

Simplified Method for Determining Polychlorinated Biphenyls, Phthalates,and Hexachlorocyclohexanes in Air

1987 ◽  
Vol 70 (4) ◽  
pp. 721-723
Author(s):  
Vincent B Stein ◽  
Thakor A Amin ◽  
Rajinder Singh Narang
Keyword(s):  
Gas Chromatography ◽  
Polychlorinated Biphenyls ◽  
Mobile Phase ◽  
Capillary Column ◽  
Fused Silica ◽  
The Other ◽  
Simplified Method ◽  
Fused Silica Capillary ◽  
Silica Capillary Column ◽  
Silica Capillary

Abstract A simplified method for determining polychlorinated biphenyls (PCBs), phthalates, and benzene hexachlorides (BHCs) in air has been developed. Florisil is used as the adsorbent, and compounds are elated by liquid chromatography with 10% 2-propanol in hexane. PCBs are separated from phthalates plus BHCs on a cyanopropyl column with a gradient containing 10% 2-propanol in hexane and 100% hexane as the mobile phase. Two fractions are collected: one contains PCBs and the other contains phthalates plus BHCs, which ve then determined by gas chromatography using a 63Ni electroncapture detector and a DB-5-bonded, fused-silica capillary column.

Evaluation of Mercury in Environmental Samples by a Supramolecular Solvent–Based Dispersive Liquid–Liquid Microextraction Method Before Analysis by a Cold Vapor Generation Technique

2017 ◽  
Vol 100 (3) ◽  
pp. 782-788 ◽  
Author(s):  
Jamshed Ali ◽  
Mustafa Tuzen ◽  
Tasneem G Kazi
Keyword(s):  
Certified Reference Materials ◽  
Experimental Conditions ◽  
Simple Method ◽  
Cold Vapor ◽  
Solvent Phase ◽  
Supramolecular Solvent ◽  
Thar Coalfield ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Abstract Supramolecular solvent–based dispersive liquid–liquid microextraction was used as a preconcentration method for the determination of trace levels of Hg. This simple method accurately measured oxidized HgII content inclaystone and sandstone samples obtained from the Thar Coalfield in Pakistan. Cold vapor atomic absorption spectrometry was used as the detection technique because it is reliable and accurate. The HgII in acidic media forms a complexwith dithizone (DTz) in the presence of supramolecular solvent (tetrahydrofuran and 1-undecanol), forming reverse micelles. Formation of the Hg-DTz complex was achieved to increase the interactions with the supramolecular solvent phase at pH 2.5 under the optimized experimental conditions. After additionof the supramolecular solvent to the aqueous solution, the micelles were uniformly mixed using a vortex mixer. The cloudy solution was centrifuged, and the Hg-DTz complex was extracted into the supramolecular solvent phase. Under optimized experimental conditions, the LOD and enrichment factor were foundto be 5.61 ng/L and 77.8, respectively. Accuracy of the developed method was checked with Certified Reference Materials. The developed method was successfully applied for the determination of HgII in claystone and sandstone samples from the Block VII and Block VIII areas of the Thar Coalfield on the basis of depth.

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