scholarly journals A Method to Determination of Lead Ions in Aqueous Samples: Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Method Based on Solidification of Floating Organic Drop and Back-Extraction Followed by FAAS

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Çiğdem Arpa ◽  
Itır Aridaşir
Keyword(s):  
Aqueous Phase ◽  
Lead Ions ◽  
Extraction Temperature ◽  
Back Extraction ◽  
Extraction Solvent ◽  
Extraction Step ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Ultrasound-assisted dispersive liquid-liquid microextraction method based on solidification of floating organic drop and back-extraction (UA-DLLME-SFO-BE) technique was proposed for preconcentration of lead ions. In this technique, two SFODME steps are applied in sequence. The classical SFODME was applied as the first step and then the second (back-extraction) step was applied. For the classical SFODME, Pb ions were complexed with Congo red at pH 10.0 and then extracted into 1-dodecanol. After this stage, a second extraction step was performed instead of direct determination of the analyte ion in the classical method. For this purpose, the organic phase containing the extracted analyte ions is treated with 1.0 mol·L−1HNO3solution and then exposed to ultrasonication. So, the analyte ions were back-extracted into the aqueous phase. Finally, the analyte ions in the aqueous phase were determined by FAAS directly. Owing to the second extraction step, a clogging problem caused by 1-dodecanol during FAAS determination was avoided. Some parameters which affect the extraction efficiency such as pH, volume of extraction solvent, concentration of complexing agent, type, volume, and concentration of back-extraction solvent, effect of cationic surfactant addition, effect of temperature, and so on were examined. Performed experiments showed that optimum pH was 10.0, 1-dodecanol extraction solvent volume was 75 μL, back-extraction solvent was 500 μL, 1.0 mol·L−1HNO3, extraction time was 4 min, and extraction temperature was 40°C. Under optimum conditions, the enhancement factor, limit of detection, limit of quantification, and relative standard deviation were calculated as 81, 1.9 μg·L−1, 6.4 μg·L−1, and 3.4% (for 25 μg·L−1Pb2+), respectively.

Simultaneous Determination of Four Plant Hormones in Soil by Ultrasound-Assisted Ionic Liquid Based Dispersive Liquid-Liquid Microextraction

2014 ◽  
Vol 675-677 ◽  
pp. 181-184 ◽  
Author(s):  
Gui Qi Huang ◽  
She Ying Dong ◽  
Zhen Yang ◽  
Ting Lin Huang
Keyword(s):  
Ionic Liquid ◽  
Plant Hormones ◽  
High Performance ◽  
Extraction Solvent ◽  
Target Analytes ◽  
Relative Standard ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

An ultrasound-assisted ionic liquid based dispersive liquid-liquid microextraction (UA-IL-DLLME) was developed for the determination of four plant hormones (6-benzyladenine (6-BA), kinetin (6-KT), 2, 4-dichlorophenoxy acetic acid (2, 4-D) and uniconazole (UN)) in soil, using high performance liquid chromatography (HPLC)-diode array detection (DAD). Several important parameters including the type and volume of extraction solvent, the volume of disperser solvent, ultrasound time, pH of the solution and salt effect were studied and optimized. Under optimum conditions, the limits of detections (LODs) for the target analytes were in the range of 0.002-0.01 μg g-1. And satisfactory recoveries of the target analytes in the soil samples were 79.3-96.7 %, with relative standard deviations (RSD, n=5) that ranged from 4.3 to 6.7%.

Two dispersive liquid–liquid microextraction methods coupled with gas chromatography–mass spectrometry for the determination of organophosphorus pesticides in field water

2014 ◽  
Vol 11 (6) ◽  
pp. 661 ◽  
Author(s):  
Shang-Ping Chu ◽  
Chun-Kai Huang ◽  
Pai-Shan Chen ◽  
Shang-Da Huang
Keyword(s):  
Mass Spectrometry ◽  
Organophosphorus Pesticides ◽  
Extraction Methods ◽  
Gas Chromatography Mass Spectrometry ◽  
Aqueous Samples ◽  
Extraction Solvent ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Environmental context Conventional sample pretreatment for the determination of pesticides in environmental samples is time consuming and labour intensive. We report two dispersive liquid–liquid micro-extraction methods that provide rapid homogeneous emulsification in aqueous samples within 2min. These simple and environmentally friendly extraction methods are particularly suitable for the measurement of organophosphorus pesticides in field water. Abstract The methods up-and-down shaker-assisted dispersive liquid–liquid microextraction (UDSA-DLLME) and water with low concentration of surfactant in dispersed solvent-assisted emulsion dispersive liquid–liquid microextraction (WLSEME) were developed for the analysis of 13 organophosphorus pesticides (OPPs) in water samples by gas chromatography–mass spectrometry (GC-MS). UDSA-DLLME required only 14μL of 5-methyl-1-hexanol as the extraction solvent. The use of an up-and-down shaker allowed homogeneous and rapid emulsification of aqueous samples. OPP extraction was completed in 2min. In WLSEME, a mixture containing 9μL of the extraction solvent (1-heptanol) and 250μL of water as the dispersed solvent (containing 10mgL–1, Triton X-100) was withdrawn and expelled four times within 10s using a microsyringe to form a cloudy emulsion in the syringe. This emulsion was then injected into 5mL of aqueous sample spiked with all of the above OPPs. The total extraction time was ~0.5min. After optimisation, the linear range of the method was 0.1–100μgL–1 for UDSA-DLLME and 0.05–100μgL–1 for WLSEME. The coefficient of determination was greater than 0.9958. The limits of detection ranged from 0.040 to 0.069μgL–1 for UDSA-DLLME and 0.020 to 0.035μgL–1 for WLSEME. Analyses of river water, lake water and underground water had absolute recoveries of 34 to 96% and relative recoveries of 84 to 115% for both methods. Other emulsification methods such as vortex-assisted, ultrasound-assisted and manual-shaking-enhanced ultrasound-assisted methods were also compared against the proposed UDSA-DLLME and WLSEME methods. The results reveal that UDSA-DLLME and WLSEME provided higher extraction efficiency and precision.

Dispersive liquid–liquid microextraction with back extraction using an immiscible organic solvent for determination of benzodiazepines in water, urine, and plasma samples

RSC Advances ◽  
2016 ◽  
Vol 6 (115) ◽  
pp. 114198-114207 ◽  
Author(s):  
Mahnaz Ghambarian ◽  
Fateme Tajabadi ◽  
Yadollah Yamini ◽  
Ali Esrafili
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Back Extraction ◽  
Plasma Samples ◽  
Extraction Step ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A novel DLLME method with a back extraction step using two immiscible organic solvents for obtaining higher clean-up than the conventional DLLME method.

Ultrasound-Assisted Dispersive Liquid–Liquid Microextraction and Capillary Electrophoretic Determination of Tramadol in Human Plasma

2020 ◽  
Vol 16 ◽  
Author(s):  
Paria Habibollahi ◽  
Azam Samadi ◽  
Alireza Garjani ◽  
Samad Shams Vahdati ◽  
Hamid-Reza Sargazi ◽  
...  
Keyword(s):  
Human Plasma ◽  
Limit Of Detection ◽  
Plasma Samples ◽  
Extraction Solvent ◽  
Human Plasma Samples ◽  
Good Repeatability ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

BACKGROUND: Tramadol, (±)-trans-2-[(dimethylamino) methyl]-1-(3-methoxyphenyl) cyclohexanol, is a synthetic centrally acting analgesic used in the treatment of moderate to chronic pain. Tramadol like other narcotic drugs is used for the treatment of pain and also may be abused. Its overdose can cause adverse effects such as dizziness, vomiting, and nausea. The aim of this paper is to develop a sample preparation method for the determination of tramadol in human plasma samples followed by CE analysis. METHODS: Ultrasound assisted-dispersive liquid–liquid microextraction using binary mixed extractant solvent (chloroform and ethyl acetate) was used for extraction of one hundred microliters of tramadol spiked human plasma samples and in real human plasma samples obtained from the patients with abuse of tramadol. After evaporation the extractant solvent, the residue was reconstituted in 100 µL deionized water and subsequently analyzed by CE-UV. RESULTS: The developed method has remarkable characteristics including simplicity, good repeatability and appreciable accuracy. Under the best extraction conditions, low limit of detection at 7.0 µg per liter level with good linearity in the range of 0.02–10 µg mL‒1 was obtained. CONCLUSION: UA-DLLME using a binary mixed extraction solvent was established for the determination of tramadol in human plasma samples via CE method with UV-detection. In addition, the analysis of tramadol in some plasma samples of patients with abuse of tramadol indicated that the method has acceptable performance for determination of tramadol in plasma samples which indicate that the method is suitable for clinical applications.

Simple and Rapid Dual-Dispersive Liquid–Liquid Microextraction as an Innovative Extraction Method for Uranium in Real Water Samples Prior to the Determination of Uranium by a Spectrophotometric Technique

2017 ◽  
Vol 100 (6) ◽  
pp. 1848-1853 ◽  
Author(s):  
Naeemullah Khan ◽  
Mustafa Tuzen ◽  
Tasneem Gul Kazi
Keyword(s):  
Aqueous Phase ◽  
Matrix Effects ◽  
Extraction Solvent ◽  
Dispersive Liquid Liquid Microextraction ◽  
Optimized Conditions ◽  
First Time ◽  
Extracting Solvent ◽  
Liquid Microextraction ◽  
Liquid Process

Abstract An innovative, rapid, and simple dual-dispersive liquid–liquid microextraction (DDLL-ME) approach was used to extract uranium from real samples for the first time. The main objective of this study was to disperse extraction solvent by using an air-agitated syringe system to overcome matrix effects and avoid dispersion of hazardous dispersive organic solvents by using heat. The DDLL-ME method consisted of two dispersive liquid–liquid extraction steps with chloroform as the extracting solvent. Uranium formed complexes with 4-(2-thiazolylazo) resorcinol in the aqueous phase and was extracted in extracting solvent (chloroform) after the first dispersive liquid–liquid process. Uranium was then back-extracted in the acidic aqueous phase in a second dispersive liquid–liquid process. Finally, uranium was determined by a spectrophotometric detection technique. The variables that played a key role in the proposed method were studied and optimized. The LOD and sensitivity enhancement factor for uranium were found to be 0.60 µg/L and 45, respectively, under optimized conditions. Calibration graphs were found to be linear in the range of 5.0–600 µg/L. The RSD was 2.5%. Reliability of the proposed method was verified by analyzing certified reference material TM-28.3.

Sensitive and accurate determination of neurotransmitters from in vivo rat brain microdialysate of Parkinson's disease using in situ ultrasound-assisted derivatization dispersive liquid–liquid microextraction by UHPLC-MS/MS

RSC Advances ◽  
2016 ◽  
Vol 6 (110) ◽  
pp. 108635-108644 ◽  
Author(s):  
Xian-En Zhao ◽  
Yongrui He ◽  
Ping Yan ◽  
Na Wei ◽  
Renjun Wang ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Rat Brain ◽  
Accurate Determination ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

In situ UA-DDLLME coupled with UHPLC-MS/MS has been developed for simultaneous determination of neurotransmitters and baicalein from Parkinson's disease rats.

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