Ionic liquid foam floatation coupled with ionic liquid dispersive liquid–liquid microextraction for the separation and determination of estrogens in water samples by high‐performance liquid chromatography with fluorescence detection

A method of ionic liquid salt aqueous two-phase extraction coupled with high-performance liquid chromatography has been developed for the analysis of seven rare ginsenosides including Rg6 , F4 , 20(S)-Rg3 , 20(R)-Rg3 , Rk3 , Rk1 , and Rg5 in Xue-Sai-Tong injection. The injection was mixed with ionic liquid 1-butyl-3-methylimidazolium bromide aqueous solution, and a mixture was obtained. With the addition of sodium dodecyl sulfate and dipotassium phosphate into the mixture, the aqueous two-phase mixture was formed after ultrasonic treatment and centrifuged. Rare ginsenosides were extracted into the upper phase. To obtain a high extraction factors, various influences were considered systematically, such as the volume of ionic liquid, the category and amount of salts, the amount of sodium dodecyl sulfate, the pH value of system, and the time of ultrasonic treatment. Under the optimal condition, rare ginsenosides in Xue-Sai-Tong injection were enriched and detected, the recoveries of seven rare ginsenosides ranged from 90.05 to 112.55%, while relative standard deviations were lower than 2.50%. The developed method was reliable, rapid and sensitive for the determination of seven rare ginsenosides in the injections.

Section: Introductionmentioning

confidence: 99%

Ionic liquid and aqueous two‐phase extraction based on salting‐out coupled with high‐performance liquid chromatography for the determination of seven rare ginsenosides in Xue‐Sai‐Tong injection

Jin

Wang

et al. 2015

“…Foam separation has been used as a technique to separate mixtures based on their selective adsorption to a bubble surface. Separations of microparticles and solutes according to their foam affinity have been carried out in the past using various designs of tubular columns . In the tubing space, however, wet foams form, which carry an excess of mother liquid (the starting crude sample containing the impurities in solvent) that contaminate the foam fractions.…”

Section: Introductionmentioning

confidence: 99%

A novel foam based separation strategy for extracting minute target impurities

Sadegh

Dasarathy

Ito

2019

The purpose of this study was to extract impurities from compounds using a simple separatory bottle to purify target compounds with a foam column and allow for the further characterization of impurities. Charged dyes were used as target compounds due to the ease of detection of dyes and isolated impurities. Foaming agents were used in a glass bottle with a modified cap to separate a target impurity using an appropriately charged ligand. By passing N2 gas through the solution, the surfactants sodium dodecyl sulfate and cetylpyridinium chloride generated foams that separated the dyes, Methylene blue and Orange G, respectively, from a solution containing both dyes. Sodium dodecyl sulfate condensed Methylene blue from the solution with high purity while cetylpyridinium chloride condensed Orange G with less purity. A range of concentrations (0.01–0.5 mmol/L) of dyes were used for separation. The condensability (volume and/or concentration) of the target compound increased as its concentration decreased. This novel separation method is a simple, rapid, inexpensive, and effective way to prepare samples and allows for the characterization of these impurities using sensitive analytical detection techniques.

“…Sample preparation techniques such as LLE and SPE have been the standard methods for the extraction of analytes from aqueous samples; however, they require large volumes of organic solvents and time‐consuming operation. Recently, newly developed sample pretreatment methods, including cloud point extraction , stir bar sorptive extraction , membrane extraction , SPME , dispersive liquid‐phase microextraction , or dispersive liquid–liquid microextraction (DLLME) have been reported for detecting estrogens either in pharmaceutical formulations, food samples, environment matrices, or in biological samples.…”

Section: Introductionmentioning

confidence: 99%

Dispersive liquid–liquid microextraction as an effective preanalytical step for the determination of estradiol in human urine

Kupcová

Reiffová

2017

In this work, a fast and effective dispersive liquid-liquid microextraction was developed for the isolation and preconcentration of free 17 β-estradiol, the main human estrogen, from real human urine samples. To optimize the extraction technique, few important parameters such as type and volume of extraction and dispersive solvents, centrifugation conditions, effect of salt addition, and extraction time were studied. Optimal conditions were obtained when injecting 600 μL mixture of tetrachloromethane as extraction solvent and ethanol as dispersive solvent (1:5, v/v) into 2 mL of urine containing 8% NaCl and following centrifugation at 10 000 rpm, thus reaching enrichment factor 28 and extraction recovery 98% for estradiol. Procedure was evaluated by means of high-performance liquid chromatography with UV detection (λ = 280 nm) using a C-18 column and methanol/water (60:40, v/v) as the mobile phase. The method was linear within the concentration range 1.0-250.0 mg/L (r = 0.9997) and provided a limit of detection of 0.25 mg/L. The proposed method was applied to the determination of free estradiol in real human pregnancy urine.