scholarly journals β-Cyclodextrin Assisted Liquid–Liquid Microextraction Based on Solidification of the Floating Organic Droplets Method for Determination of Neonicotinoid Residues

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3954
Author(s):  
Vichapong ◽  
Moyakao ◽  
Kachangoon ◽  
Burakham ◽  
Santaladchaiyakit ◽  
...  
Keyword(s):  
Pesticide Residues ◽  
Limit Of Detection ◽  
Environment Friendly ◽  
Extraction Solvent ◽  
Salt Addition ◽  
High Enrichment ◽  
Sensitive Determination ◽  
Cloudy Solution ◽  
Liquid Microextraction

An efficient and environment-friendly microextraction method, namely, β-cyclodextrin assisted liquid–liquid microextraction, based on solidification of the floating organic droplets method coupled with HPLC is investigated for the sensitive determination of trace neonicotinoid pesticide residues. In this method, β-cyclodextrin is used as a disperser solvent, while 1-octanol is selected as an extraction solvent. β-cyclodextrins was found to decrease interfacial tension and increase the contact area between the organic and water phases with the help of centrifugation. A cloudy solution was rapidly formed and then centrifuged to complete phase separation. Various key parameters influencing extraction efficiency were systematically investigated and optimized; they include salt addition, concentration of β-cyclodextrin, and volume of extraction solvent (1-octanol). Under optimum conditions, good linearity was obtained with coefficient for determination (R2) greater than 0.99. A low limit of detection, high enrichment factor, and good recovery (83 – 132) were achieved. This proves that the proposed method can be applied to determine trace neonicotinoid pesticide residues in natural surface water samples.

Vortex-Assisted Dispersive Liquid–Liquid Microextraction Coupled with Deproteinization for Determination of Nateglinide in Human Plasma Using HPLC/UV

2020 ◽  
Author(s):  
Mohamed A Hammad ◽  
Amira H Kamal ◽  
Reham E Kannouma ◽  
Fotouh R Mansour
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Salt Addition ◽  
Relative Standard ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Abstract A validated method for preconcentration and determination of nateglinide in plasma was developed using vortex-assisted dispersive liquid–liquid microextraction. Different variables that affect extraction efficiency were studied and optimized, including type and volume of extractant, type and volume of disperser, pH of diluent, salt addition effect, centrifugation and vortex time. Nateglinide was extracted using 30 μL of 1-octanol as an extractant and 200 μL of methanol as a disperser. The enrichment factor reached 330 under the optimum conditions. High-performance liquid chromatography/ultraviolet was used for detection using phosphate buffer (pH 2.5, 10 mM): acetonitrile (45:55, v/v) as a mobile phase at a flow rate of 1 mL/min. The method was linear over the range of 50–20,000 ng/mL with a limit of detection of 15 ng/mL (signal-to-noise ratio = 3). Intra- and inter-day precision had %relative standard deviation <6% (n = 3) and the %recoveries were found to be between 102.5 and 105.9%. The proposed method is simple, sensitive, eco-friendly, cost-effective and powerful for microextraction of nateglinide from human plasma samples.

scholarly journals Development of Dispersive Liquid-Liquid Microextraction method combined with UV spectrophotometry for the Determination of Malathion Pesticide

2018 ◽  
Vol 28 (2) ◽  
pp. 93
Author(s):  
Wijdan Shakir Khayoon
Keyword(s):  
Limit Of Detection ◽  
Binary Solution ◽  
Calibration Graph ◽  
Uv Spectrophotometry ◽  
Reaction Conditions ◽  
Extraction Solvent ◽  
Salt Addition ◽  
Novel Method ◽  
Dispersive Liquid Liquid Microextraction

A simple and novel method was developed by combination of dispersive liquid-liquid microex-traction with UV spectrophotometry for the preconcentartion and determination of trace amount of malathion. The presented method is based on using a small volume of ethylenechloride as the extraction solvent was dissolved in ethanol as the dispersive solvent, then the binary solution was rapidly injected by a syringe into the water sample containing malathion. The important parame-ters, such the type and volume of extraction solvent and disperser solvent, the effect of extraction time and rate, the effect of salt addition and reaction conditions were studied. At the optimum conditions, the calibration graph was linear in the range of 2-100 ng mL-1 of malathion with a limit of detection of 0.8 ng L-1. In addition, the enrichment factor was 30. The developed method was successfully applied for the determination of malathion pesticide in water samples

Dispersive Liquid-Liquid Microextraction Coupled with Gas Chromatography for the Determination of Orthochlorophenol in Environmental Water Samples

2012 ◽  
Vol 518-523 ◽  
pp. 1379-1382
Author(s):  
Ying Chun Yang ◽  
Qian Sun ◽  
Chong Shu Yi ◽  
Zhi Xiang Ye ◽  
Li Mo
Keyword(s):  
Gas Chromatography ◽  
Water Samples ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Extraction Solvent ◽  
Salt Addition ◽  
Relative Standard ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A rapid and effective method, the dispersive liquid-liquid microextraction(DLLME) with gas chromatography, has been developed for the extraction and determination of OCP in environmental water samples. The factors relevant to the efficiency of DLLME were investigated and optimized. Under the optimum conditions, such as 150μL of dichloromethane as extraction solvent, 1.2 mL acetone as dispersive agent, 8 minutes extraction time, and without salt addition, the linear response of this method was in the range of 0.5～5000μg L−1 (r = 0.9981), the relative standard deviation (RSD) for 500μg L−1 and 1000μg L−1 of OCP was 5.2% and 12.6% (n = 6), respectively. The detection limit (3σ) was 0.08 μg L−1. The developed method was successfully applied to the determination of trace amount of OCP in three kinds of real environmental water samples, the spiked recoveries were in the range of 87.4%～108.0%.

Development of a preconcentration method for indomethacin in natural waters using dispersive liquid–liquid microextraction based on solidification of floating organic drop technique

2018 ◽  
Vol 53 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Nesrin Topaç ◽  
Cennet Karadaş ◽  
Derya Kara
Keyword(s):  
Water Samples ◽  
Natural Waters ◽  
Limit Of Detection ◽  
Tap Water ◽  
Chloride Concentration ◽  
Extraction Solvent ◽  
Dispersive Liquid Liquid Microextraction ◽  
Preconcentration Method ◽  
Liquid Microextraction

Abstract A new dispersive liquid–liquid microextraction method based on the solidification of a floating organic drop was developed for the preconcentration of indomethacin in natural waters followed by ultraviolet-visible (UV-Vis) spectrophotometric detection. 1-undecanol and ethanol were used as the extraction solvent and the disperser solvent, respectively. An investigation of the main experimental parameters that may affect the extraction efficiency, such as sample pH, volume of extraction and disperser solvents, sodium chloride concentration and centrifugation time was undertaken. The effect of interfering ions on the recovery of indomethacin was also examined. Under optimal conditions without any preconcentration, the limit of detection was 17.9 μg/L calculated from LOD = 3 Sb/m and was also calculated as 74.9 μg/L from the regression values of the calibration line using 3.19 Se/m. The proposed preconcentration method was successfully applied to determination of indomethacin in spiked tap water and river water samples. The recovery values for spikes added to water samples were between 94.5 and 103.0%.

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.

scholarly journals Spectrophotometric monitoring of nitrite in seawater after liquid microextraction of its derivative with 2,3-diaminonaphthalene

2015 ◽  
Vol 52 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Mir Mahdi Zahedi ◽  
Amir Hosein Amiri ◽  
Mahmoud Nasiri
Keyword(s):  
Limit Of Detection ◽  
Optimum Conditions ◽  
Nitrite Concentration ◽  
Spectrophotometric Detection ◽  
Factors Affecting ◽  
Extraction Solvent ◽  
The North ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A simple dispersive liquid–liquid microextraction based on solidification of floating organic droplets coupled with spectrophotometric detection was developed for the determination of nitrite in Chabahar Bay seawater. In the preparation procedure, 2,3-diaminonaphthalene as derivatization reagent reacts with nitrite in acidic medium to form a photometric center of 1-[H]-naphthotriazole (NAT). Product material (NAT) was extracted by dispersive liquid–liquid microextraction with 1-dodecanol as extraction solvent and after centrifugation, the floated droplet was solidified in an ice bath and was easily removed for analysis at λmax = 358 nm. Several important factors affecting the microextraction efficiency were optimized in artificial seawater as a best simulation media. Under the optimum conditions, the absorbance of NAT was linear with nitrite concentrations ranging from 0.1 to 11 μg/mL in seawater. Figures of merit of method such as enrichment factor (52), limit of detection (0.094 μg/mL), and repeatability (N = 6, %RSD = % 5) were evaluated as appropriate. Determination of nitrite in Chabahar coastal zone showed that nitrite concentration varied in the range of 0.77–1.76 μg/mL with an increase of concentration from South to the North of Bay.

Rational design of an ionic liquid dispersive liquid–liquid micro-extraction method for the detection of organophosphorus pesticides

The Analyst ◽  
2019 ◽  
Vol 144 (6) ◽  
pp. 2166-2172 ◽  
Author(s):  
Dingkun Lu ◽  
Chang Liu ◽  
Jingjing Deng ◽  
Xinguang Zhou ◽  
Guoyue Shi ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Extraction Method ◽  
High Performance ◽  
Rational Design ◽  
Organophosphorus Pesticides ◽  
Extraction Solvent ◽  
Sensitive Determination ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

In this study, a functionalized ionic liquid (IL), [MimCH2COOCH3][NTf2] was rationally designed and explored as an extraction solvent in dispersive liquid–liquid microextraction (DLLME) combined with ultra-high performance liquid chromatography (UHPLC) for the sensitive determination of organophosphorus pesticides (OPs).

scholarly journals Determination of Morin and Quercetin in Fruit Juice Samples using Air-Assisted Liquid-Liquid Microextraction Based on Solidification of Floating Organic Droplet and HPLC-UV

2020 ◽  
Vol 67 (4) ◽  
pp. 1092-1099
Author(s):  
Armin Fallah ◽  
Mohammad Reza Hadjmohammadi
Keyword(s):  
Fruit Juice ◽  
Limit Of Detection ◽  
Linear Calibration ◽  
Extraction Solvent ◽  
Relative Standard ◽  
Burman Design ◽  
Optimized Conditions ◽  
Plackett Burman Design ◽  
Liquid Microextraction

In this study, a rapid and efficient method has been used for the extraction and determination of morin and quercetin in fruit juice samples based on air-assisted liquid-liquid microextraction based on solidification of floating organic droplet and HPLC-UV. The effects of 7 important parameters on the extraction recovery were examined and were optimized by Plackett-Burman design and Central Composite design. According to the Plackett-Burman design results, ionic strength of the sample solutions, the aspiration/dispersion cycles, and the rate and time of centrifuge did not show significant effects on the extraction of morin and quercetin. The optimized conditions of extraction were as follows; the volume of the extraction solvent of 83.6 μL, pH of 4.34 for the sample, and 1-undecanol as extraction solvent. Under these conditions, the linear calibration curve was in the ranges of 1–1000 ng/mL and 0.5–1000 ng/mL for morin and quercetin, respectively, with the determination coefficient values above 0.99. The limit of detection of morin and quercetin was 0.3 and 0.2 ng/mL, respectively. The extraction recoveries for 10 ng/mL of morin and quercetin were 98.9% and 96.5%, respectively; while, relative standard deviations (n = 3) were lower than 3.2%.

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