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A microextraction approach for rapid extraction and separation of Mn(II) and Co(II) using saponified

《化学科学与工程前沿（英文）》 2022年第16卷第6期页码 963-972 doi: 10.1007/s11705-021-2081-7

摘要： In this paper, we proposed a microextraction approach for the extraction and separation of Mn(II) and Co(II) from sulfate solution simulating leachate of spent lithium-ion battery cathode materials using saponified di-(2-ethylhexyl)phosphoric acid system. The effects of the following operational variables were investigated: equilibrium pH, tri-n-butyl phosphate concentration, saponification rate, two-phase ratio and residence time. The results showcased that the microextractor can reach the extraction equilibrium within 20 s, thereby greatly reducing necessary extraction time comparing to that of conventional processes. The volumetric mass transfer coefficient showed 8–21 times larger than that of batch device. With the help of microextractor, 95% of Mn(II) was extracted with a single theoretical stage at a chosen two-phase ratio of 3:1, and the separation factor

β Mn / Co

was as large as 65.5. In the subsequent stripping step, more than 99% of manganese from loaded phase was easily stripped under optimal conditions. The microextraction approach greatly enhances the mass transfer while enabling a continuous and controllable extraction process within a simple structure design. When extracting spent electrode material with microextractors, the comprehensive recovery of mangenese can reach 96%. The microextraction approach has a good applicability in the spent lithium-ion battery cathode materials recycling at both bench and industrial scales.

关键词： extraction equilibrium mass transfer coefficient microextraction multicomponent extraction di-(2-ethylhexyl)phosphoric acid

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Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determination

Qingyun CHANG, Jingwen ZHANG, Xin DU, Jingjun MA, Jingci LI,

《环境科学与工程前沿（英文）》 2010年第4卷第2期页码 187-195 doi: 10.1007/s11783-010-0030-7

摘要： A simple and efficient liquid-phase microextraction (LPME) technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction (USAE-SFODME) combined with flame atomic absorption spectrometry, for the extraction and determination of trace copper in water samples. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. Microextraction efficiency factors (including extraction solvent type, extraction volume, time, temperature, and pH), the amount of the chelating agent, and salt effect were investigated and optimized. Under the optimum extraction conditions, figures of merit of the proposed method were evaluated. The calibration graph was linear in the range of 20–600 g·L with a detection limit of 0.76 g·L. The relative standard deviation (R.S.D) for ten replicate measurements of 20 and 400 g·L of copper was 3.83% and 2.65%, respectively. Finally, the proposed method was applied to tap water, river water, and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.

关键词： ultrasound-assisted emulsification solidified floating organic drop microextraction flame atomic absorption spectrometry preconcentration copper

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Trace analysis of off-flavor/odor compounds in water using liquid-liquid microextraction coupled with

Jian LU,Paul S. WILLS,P. CHRIS WILSON

《环境科学与工程前沿（英文）》 2016年第10卷第3期页码 477-481 doi: 10.1007/s11783-015-0820-z

摘要： A rapid, inexpensive and laboratory friendly method was developed for analysis of off-flavor/odor compounds in fresh and salt water using gas chromatography with chemical ionization-tandem mass spectrometry. Off-flavor/odor compounds included geosmin, 2-methylisoborneol (MIB), 2-isobutyl-3-methyoxypyrazine (IBMP), and 2-isopropyl-3-methoxypyrazine (IPMP). Using this method, a single sample can be extracted within minutes using only 1 mL of organic solvent. The ion transitions for IPMP, IBMP, MIB, and geosmin were 153>121, 167>125, 152>95, and 165>109, respectively. The linearity of this method for analyzing MIB ranged from 4 to 200 ng·L , and from 0.8 to 200 ng·L for the other analytes. Method recoveries ranged from 97% to 111% and percent relative standard deviations ranged from 3% to 9%, indicating that the method is accurate, precise, and reliable.

关键词： off-flavor/odor compounds liquid-liquid microextraction gas chromatography-tandem mass spectrometry