Development of a novel hollow-fiber liquid-phase microextraction based on oil-in-salt and its comparison with conventional one

et al. 2019

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A three-phase hollow-fiber liquid-phase microextraction based on deep eutectic solvent as acceptor phase was developed and coupled with high-performance capillary electrophoresis for the simultaneous extraction, enrichment, and determination of main active compounds (hesperidin, honokiol, shikonin, magnolol, emodin, and β,β ′dimethylacrylshikonin) in a traditional Chinese medicinal formula. In this procedure, two hollow fibers, impregnated with n-heptanol/n-nonanol (7:3, v/v) mixture in wall pores as the extraction phase and a combination (9:1, v/v) of methyltrioctylammonium chloride/glycerol (1:3, n/n) and methanol in lumen as the acceptor phase, were immersed in the aqueous sample phase. The target analytes in the sample solution were first extracted through the organic phase, and further back-extracted to the acceptor phase during the stirring process. Important extraction parameters such as types and composition of extraction solvent and deep eutectic solvent, sample phase pH, stirring rate, and extraction time were investigated and optimized. Under the optimal conditions, detection limits were 0.3-0.8 ng/mL with enrichment factors of 6-114 for the analytes and linearities of 0.001-13 μg/mL (r 2 ≥ 0.9901). The developed method was successfully applied to the simultaneous extraction and concentration of the main active compounds in a formula of Zi-Cao-Cheng-Qi decoction with the major advantages of convenience, effectiveness, and environmentally friendliness. K E Y W O R D Sdeep eutectic solvents, high performance liquid chromatography, hollow-fiber liquid-phase microextraction, traditional Chinese medicine Article Related Abbreviations: 2p-HF-LPME, two-phase hollow-fiber liquid-phase microextraction; 3p-HF-LPME, three-phase hollow-fiber liquid-phase

Section: Resultsmentioning

confidence: 99%

Three‐phase hollow‐fiber liquid‐phase microextraction based on deep eutectic solvent as acceptor phase for extraction and preconcentration of main active compounds in a traditional Chinese medicinal formula

Xue

Wang

et al. 2019

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“…In recent years, our research group has studied the influence of salting‐out effect occurring in different location on EF of target analyte, and proposed oil‐in‐salt liquid phase microextraction on permutite and oil‐in‐salt hollow fiber liquid phase microextraction . In two methods, the salting‐out effect occurred between organic solvent and sample solution, which significantly improved EFs of the target analytes than the salting‐out effect occurred in sample solution.…”

Section: Introductionmentioning

confidence: 99%

Ballpoint connector‐protected salt‐oil‐salt liquid phase microextraction for concentration and enrichment of trace anthraquinone compounds in rhubarb

et al. 2019

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This study proposed a new ballpoint connector-protected salt-oil-salt liquid phase microextraction for extraction and enrichment of trace rhein and chrysophanol in rhubarb prior to determination of the analytes by high performance liquid chromatography. In this study, a handy ballpoint connector (between ballpoint tip and ink chamber) was used as extraction device, in which its cavity was filled with n-octanol, and the bare n-octanol in its two opening ends was covered with a thin layer of sodium chloride film. The design subtly assembled salt film onto ballpoint connector for extraction and enrichment, which greatly improved the enrichment factors of the target analytes. Moreover, the novel procedure and its extraction mechanism were described and analyzed, and several crucial parameters reflecting the extraction effect were investigated and optimized. Under optimum conditions, high enrichment factors (247 and 127), good linearities with r ≥ 0.9998, limits of detection (0.6-1.1 ng/mL), relative standard deviations of intra-and interday (2.2-8.8% and 4.3-8.9%), and average recoveries (97.6-98.1%), were obtained, respectively. The proposed method can not only eliminate the negative effects from viscosity and ion strength at high salt concentration of sample phase, but also make salting-out effect be focused on small area so as to maximize the extraction effect.

“…Recently, Gao proposed an oil‐in‐salt LPME on permutite, with HPLC, for the enrichment and determination of alkaloids in Coptis chinensis . Soon afterwards, Li developed a novel oil‐in‐salt hollow fiber LPME with HPLC method and introduced it for simultaneous extraction and determination of main active compounds in Zi‐Cao‐Cheng‐Qi Decoction.…”

Section: Introductionmentioning

confidence: 99%

Salt‐assisted dispersive liquid–liquid microextraction for enhancing the concentration of matrine alkaloids in traditional Chinese medicine and its preparations

Zhang

et al. 2018

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A fast, simple, and efficient salt-assisted dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography was developed and introduced for the simultaneous enrichment, extraction, and determination of the trace levels of matrine alkaloids (sophoridine, matrine, and sophocarpine) in Sophorae Flavescentis Radix and Composite Kushen injection. Compared with conventional dispersive liquid-liquid microextraction, the proposed method, with added salt but without dispersant and centrifuging, makes the operation simpler, greener, and leads to a higher enrichment factor. The crucial parameters affecting the enrichment factors of target analytes, such as type and volume of extraction solvent, pH of sample phase, salt concentration, volume of sample phase, and extraction time, were investigated and optimized, meanwhile, the extraction mechanism of the method was analyzed and described. Under the optimized conditions, the enrichment factors of the three matrine alkaloids were 150, 178, and 227, respectively. Good linearities (r ≥ 0.9992) for all analytes, low limits of detection (less than 0.08 ng/mL), satisfactory precisions (2.1-12.3%), and accuracies (recoveries, 99.3-103.9%) were achieved. The experimental results showed that the approach is a simple, fast, green, eco-friendly, and sensitive method and can be used for the preconcentration and determination of matrine alkaloids in traditional Chinese medicines and their preparations.