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Colorimetric determination of nanomolar concentrations of silicate in natural waters after liquid-liquid extraction using methyl isobutyl ketone

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Acta Oceanologica Sinica 2008年第1期27卷 137-146页

作者： REN Jingling MI Tiezhu DOU Weiwei LIU Sumei ZHANG Jing Key Laboratory of Marine Chemistry Theory and Technology of Ministry of Education Ocean University of China Qingdao266100 China College of Environmental Science and Engineering Ocean University of China Qingdao 266100 China State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062 China

A sensitive solvent extraction method for the determination of nonamolar concentrations of silicate in natural waters is developed. According to the traditional aqueous silicate method, silicomolybdenum blue formed by the reaction between silicate and ammoni- um molydate and reduced by metol-sulfite reagent is extracted by methyl isobutyl ketone. The absorbance can be enhanced substantially up to 10-folds. The detection limit of silicate is 8 nmol/dm^3 , which is one tenth smaller than the traditional method, with the precision of 4.0% at a silicate level of 50 nmol/dm^3 and 3.2% at a silicate level of 6 μmol/dm^3. Comparing the calibration curves in the distilled water and seawater, it can be seen that the salt effect also exists in the extraction method. However, the salt effect is a linear function of the salinity and can be corrected by simple calibration. The proposed method is successfully applied to the determination of silicate in natural waters. Natural concentrations of arsenate, arsenite and phosphate cause negligible interference.

关键词： silicate colorimetric determination liquid-liquid extraction methyl isobutyl ketone

Upper-rim-modified thioether thiacalix[4]arene used for liquid-liquid extraction of Au(Ⅲ)and Pd(Ⅱ)in hydrochloric acid medium

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Chinese Journal of Chemical Engineering 2024年第2期66卷 110-118页

作者： Sheng Wan Rong Xie Jianhong Fan Kewen Tang Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China

Gold(Au)and palladium(Pd)play an increasing role in the production and human life;Therefore,it is of great significance to study their recovery.A 5,11,17,23-tetra-ethylthio-25,26,27,28-tetra-hydroxyl thiacalix[4]arene(TCAET)was synthesized specifically for the capture of Au(Ⅲ)and Pd(Ⅱ)from HCl medium by liquid-liquid *** a 0.1 mol·L^(-1)HCl medium,the transfer of Au(Ⅲ)and Pd(Ⅱ)from the aqueous phase to the organic phase was highly efficient,with a transfer ratio of 100%for Au(Ⅲ)and 98%for Pd(Ⅱ).Furthermore,the extraction equilibrium time for Au(Ⅲ)was just 5 ***'s method data demonstrated that TCAET formed complexes with Au(Ⅲ)and Pd(Ⅱ)in a ratio of 2:3 and 1:1,respectively,during the extraction *** showed high selectivity toward Pd(Ⅱ)and Au(Ⅲ)over other competing metal ***,both Au(Ⅲ)and Pd(Ⅱ)could be successfully stripped from the loaded organic phases with a 1.0 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl and 0.5 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl,*** obtained from five consecutive extraction-stripping cycles showed good reusability of TCAET toward Au(Ⅲ)and Pd(Ⅱ)*** conclusion can provide a certain reference for thiacalixarene in the recovery of precious metal species.

关键词： Thiacalixarene Upper-rim modification liquid-liquid extraction Precious metal Thioether

Trace Analysis of Anions in Perfluorodecalin by Green liquid-liquid extraction Combined with Ion Chromatography

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Journal of Analysis and Testing 2022年第3期6卷 346-351页

作者： Sheng Liu Jian Xu Yu Lu Yong Huang Zhi-Wen Fang Mei Lv Li-Tao Wang The Technical Center of Zibo Customs Zibo 255031China Suzhou Jieshitong Medical Equipment Co. Ltd.Suzhou 215000China School of Pharmacy Jining Medical UniversityJining 272000China Jining Medical University No.669Xueyuan RoadRizhao 276800China

Perfluoronaphthenes,with inert chemical and biological properties and ability to dissolve large amounts of oxygen,have received the most attention in medical ***,the excessive anion contained may cause some side ***,liquid-liquid extraction technique with shaking and ultrasonic extraction was used for the trace analysis of five anions(F^(-),Cl^(-),NO_(3)^(-),PO_(4)^(3-),SO_(4)^(2-))in perfluorodecalin using water as green *** optimum pretreatment technology and ion chromatography detection conditions were *** linearity was observed in each concentration range,and the linear correlation coefficient(R^(2))was better than *** limits of detection(S/N=3)of five anions from perfluorodecalin were 3.2,5.5,14.2,23.2 and 29.5μg/L,*** established method with high sensitivity and accuracy has been successfully appliedfor the determination of five anions in three perfluorodecalin products,which provides a basis for further development of green detection and quality standard formulation in perfluorodecalin and other fluorocarbon solvents.

关键词： Perfluorodecalin Trace analysis Anions liquid-liquid extraction Ion chromatography

Determination of polybrominated diphenyl ethers in river water by combination of liquid–liquid extraction and gas chromatography–mass spectrometry

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Chinese Chemical Letters 2014年第9期25卷 1225-1229页

作者： Weifei Zhang Xuexia Lin Hai-Fang Li Zhihua Wang Jin-Ming Lin Department of Chemistry Beijing Key Laboratory of Microanalytical Methods and InstrumentationTsinghua University State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

In this work, a reliable and sensitive method for detecting polybrominated diphenyl ethers （PBDEs） has been developed by the combination of liquid-liquid extraction and gas chromatography-mass spectrometry. PBDEs were extracted from a large volume of water by liquid-liquid extraction and purified by silica gel chromatography. In order to reduce the deviation, dibromobiphenyl was exploited as the internal standard to minimize differences among the injections. The quantification was performed using an external standard. Good linear correlation coefficients （〉0.991） and a wide linearity range （ 1,0- 500.0 ng/L） indicated the steadiness of the proposed method. Moreover, the satisfactory recovery （〉75%） suggested that successful determination of PBDEs in river water had been achieved. Furthermore, the deduction behavior of PBDEs in river water could be inferred according to the results.

关键词： Polybrominated diphenyl ethers Dibromobiphenyl GC-MS liquid-liquid extraction

Comparison of liquid-liquid extraction-thin layer chromatography with solid-phase extraction-high-performance thin layer chromatography in detection of urinary morphine

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The Journal of Biomedical Research 2011年第5期25卷 362-367页

作者： Ali Ahadi Alireza Partoazar Mohammad Hassan Abedi Khorasgani Seyed Vahid Shetab Boushehri Department of Physiology School of MedicineTehran University of Medical Sciences Department of Pharmacology School of MedicineTehran University of Medical Sciences Legal Medicine Organization of Iran Iran Department of Medical Nanotechnology School of MedicineTehran University of Medical Sciences

liquid-liquid extraction-thin layer chromatography （LLE-TLC） has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction （SPE） is gradually replacing the tra- ditional LLE method. High performance thin layer chromatography （HPTLC） has several advantages over TLC. The present work studied the higher efficiency of a new SPE-HPTLC method over that of a routine LLE-TLC method, in extraction and detection of urinary morphine. Fifty-eight urine samples, primarily identified as mor- phine-positive samples by a strip test, ＇were re-screened by LLE-TLC and SPE-HPTLC. The results of LLE-TLC and SPE-HPTLC were then compared with each other. The results showed that the SPE-HPTLC detected 74% of total samples as morphine-positive samples whereas the LLE-TLC detected 48% of the same samples. We further discussed the effect of codeine abuse on TLC analysis of urinary morphine. Regarding the importance of morphine detection in urine, the present combined SPE-HPTLC method is suggested as a replacement method for detection of urinary morphine by many reference laboratories.

关键词： morphine detection liquid-liquid extraction thin-layer chromatography solid-phase extraction highperformance thin layer chromatography

Improved determination of salicylaldoxime in water samples by liquid-liquid extraction followed by high performance liquid chromatographic analysis

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Journal of Central South University 2018年第4期25卷 701-708页

作者： KONG Qian BAI Xiu-zhi LIN Hui-ju LI Hai-pu YANG Zhao-guang College of Chemistry and Chemical Engineering Central South University

For the determination of salicylaldoxime in environmental water samples,a stable and rapid method with low detection was proposed and established,based on the liquid-liquid extraction-high performance liquid chromatography with ultraviolet *** including extraction solvent,ionic strength,solution pH,and extraction pattern were discussed for the optimal quantification of salicylaldoxime-spiked *** the described method was applied to four spiked water samples,the obtained average extraction recovery rate was found between 87%–107%and relative standard deviation was below 6%.At the same time,good linear relationships were observed for spiked water samples from 0.01 to 10μg/mL(R2=0.9993).In addition,the detection limit of salicylaldoxime was revealed between 0.003–0.008μg/mL,which is two orders of magnitude lower than previously reported ***,the presented method may be advantageous for the high-efficiency determination of salicylaldoxime in water samples.

关键词： high-performance liquid chromatography liquid-liquid extraction salicylaldoxime

Sinomenine Purification by Continuous liquid-liquid extraction Process with Centrifugal Extractors

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Advances in Chemical Engineering and Science 2020年第3期10卷 171-180页

作者： Zuren Peng Wanying Wang Xianjun Long Ping Qiu Qiaoqiao Liu Yuanxiang Yang Xuechun Yang Meili Wang Songmao Yin Xingchu Gong Hunan Zhenqin Pharmaceutical Group Co. Ltd. Huaihua China Pharmaceutical Informatics Institute College of Pharmaceutical Sciences Zhejiang University Hangzhou China

Continuous manufacturing is considered as one of the future trends of pharmaceutical engineering. In this work, continuous liquid-liquid extraction for sinomenine purification was realized with the usage of centrifugal extractors. Chloroform was used as the extractant because of the high distribution coefficient (>100). Higher extraction ratio can be obtained when using the centrifugal extractor of Model CWL50-N. The extraction ratio of the second-stage extraction was higher than that of the first-stage extraction. The extraction ratio of the second-stage countercurrent extraction was higher than that of second-stage cross-flow extraction. When chloroform phase was recycled for liquid-liquid extraction, the extraction ratio was also higher than 95%. This work can also be an example of continuous liquid-liquid extraction for the separation of other Chinese medicine components.

关键词： Sinomenine Continuous Manufacturing liquid-liquid extraction Centrifugal Extractor

Modeling of liquid-liquid extraction Process for Glycerol Purification from Biodiesel Production

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Journal of Chemistry and Chemical Engineering 2014年第10期8卷 971-977页

作者： Ignacio Contreras-Andrade Maicol Martinez-Gonzalez Luis Figueroa-Casallas Jonathan Parra-Santiago Carlos Alberto Guerrero-Fajardo Universidad Autonoma de Sinaloa Culiacan Rosales 80040 Mexico Universidad Nacional de Colombia Bogota 11001 Colombia

This paper shows some generalities about the glycerin byproduct obtained from biodiesel production process, presents an analysis of the ternary equilibrium between methanol, water and glycerol, and shows the influence that temperature has on the balance. This phase diagram illustrates ternary equilibrium at 10, 20 and 50 ℃, keeping the pressure constant at 1 atm （atmosphere） to standardize the analysis. The purpose of it is to establish the best temperature for the purification of glycerol by liquid-liquid extraction method under the ＂extraction in several stages cross flow＂ taking an initial mixture of glycerol with composition 15 wt.% water, 25 wt.% methanol and 60 wt.% glycerol. Water was used as liquid-liquid extraction solvent in order to remove as much methanol as possible from the initial solution due to the existence of a zone of insolubility between the glycerol and water in the ternary equilibrium. By this reason, two solutions are obtained, one consisting of water and methanol containing a trace of glycerin and the other consisting of water, glycerine and traces of methanol, which contain only 4.62% of the total methanol which enter in the process of liquid-liquid extraction, with 60.62% of the total glycerol, which is sent to a fractional distillation process to purify glycerin up to 98% by weight.

关键词： Ternary equilibrium liquid-liquid extraction glycerin purification.

Separation of Red (Y_2O_3: Eu^(3+)), Blue (Sr,Ca,Ba)_(10)(PO_4)_6Cl_2: Eu^(2+) and Green (LaPO_4:Tb^(3+),Ce^(3+)) Rare Earth Phosphors by liquid/liquid extraction

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Journal of Wuhan University of Technology(Materials Science) 2009年第3期24卷 418-423页

作者：梅光军 School of Resource and Environmental Engineering Wuhan University of Technology

A novel process for separation of red （Y2O3： Eu^3＋）, blue （Sr, Ca, Ba）10（PO4）6Cl2： Eu^2＋ and green （LaPO4： Tb^3＋, Ce^3＋） fine tricolor phosphor powders was established. First, the green phosphor was extracted and separated from three phosphor mixtures in heptane/DMF（N, N-Dimethylformamide） system using stearylamine or laurylamine （DDA） as the cationic surfactant. Then, after being treated with 99.5% ethanol, the blue and red phosphors could be separated in Heptane/DMF system in presence of 1-octanesulfonic acid sodium salt as the anionic surfactant. Satisfactory separation results have been achieved through two steps extractions with their artificial mixtures. The grades and recovery of separated products reached respectively as follows： red product was 95.3% and 90.9%, blue product was 90.0% and 95.2%, and green product was 92.2% and 91.8%.

关键词： rare earth phosphor liquid-liquid extraction separation