Dispersive liquid–liquid microextraction technique combined with UV–Vis spectrophotometry for determination of zirconium in aqueous samples

2020 ◽  
Vol 3 (03) ◽  
pp. 18-24
Author(s):  
Ehsan Zolfonoun

Dispersive liquid–liquid microextraction coupled with UV–Vis spectrophotometry was applied for the determination of zirconium in aqueous samples. In this method a small amount of chloroform as the extraction solvent was dissolved in pure ethanol as the disperser solvent, then the binary solution was rapidly injected by a syringe into the water sample solution containing Zr(IV), xylenol orange and cetyltrimethylammonium bromide. The formed ion-associate was extracted into the fine chloroform droplets. The detection limit for Zr(IV) was 0.010 µg mL−1. The precision of the method, evaluated as the relative standard deviation obtained by analyzing of 10 replicates, was 2.7 %. The practical applicability of the developed method was examined using natural waters and ceramic samples.

2014 ◽  
Vol 675-677 ◽  
pp. 181-184 ◽  
Author(s):  
Gui Qi Huang ◽  
She Ying Dong ◽  
Zhen Yang ◽  
Ting Lin Huang

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%.


2014 ◽  
Vol 881-883 ◽  
pp. 631-634 ◽  
Author(s):  
Jian Qi Sun ◽  
Ming Tang ◽  
Jun Dai

A simple and reliable method combining dispersive liquid-liquid microextracion (DLLME) with gas chromatography (GC) using flame ionization detection (FID) was developed for the simultaneous determination of aniline (AL),o-toluidine (o-TLD),N,N-dimethylaniline (N,N-DAL),p-chloroaniline (p-CAL), andp-nitroaniline (p-NAL) in wastewater. For this purpose, dispersive liquid-liquid microextraction (DLLME) was applied as a sample preparation technique. The DLLME conditions such as the types and volume of extraction solvent, the types and volume of the disperser solvent, pH value and salt addition were studied and optimized. The method was linear in the ranges from 2.2×10-3to 100.0 μg·mL-1for aforementioned aromatic amines withR2≥ 0.9968. The DLLME procedure allowed efficient recovery of the investigated aromatic amines ranging between 82 % and 92 % with a relative standard deviation (RSD) ≤ 3.4 for actual wastewater samples spiked with 5, 10 and 20 μg·mL-1of aromatic amines, respectively. These results showed the potential of this technique for aromatic amines monitoring in wastewater samples. Furthermore, the investigated methods are simple, reproducible, and inexpensive.


2014 ◽  
Vol 11 (6) ◽  
pp. 661 ◽  
Author(s):  
Shang-Ping Chu ◽  
Chun-Kai Huang ◽  
Pai-Shan Chen ◽  
Shang-Da Huang

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.


2012 ◽  
Vol 518-523 ◽  
pp. 1379-1382
Author(s):  
Ying Chun Yang ◽  
Qian Sun ◽  
Chong Shu Yi ◽  
Zhi Xiang Ye ◽  
Li Mo

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%.


2014 ◽  
Vol 1030-1032 ◽  
pp. 357-360 ◽  
Author(s):  
Jian Qi Sun

This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of food preservatives in drinks, including sorbic acid (SA), benzonic acid (BA) and methyl paraben (MP). For this purpose, dispersive liquid-liquid microextraction (DLLME) was applied as a sample preparation technique. The DLLME conditions such as the types and volume of extraction solvent, the types and volume of the disperser solvent, pH value and salt addition were investigated and optimized. The method was linear in the ranges from 0.5 to 100.0 μg·mL-1for abovementioned preservatives withR2≥ 0.9991. The DLLME procedure allowed efficient recovery of the analyted preservatives ranging between 91 % and 108 % with a relative standard deviation (RSD) ≤ 6.1 for the blank samples spiked with 20, 40 and 80 μg·mL-1of preservatives, respectively. The developed procedure was demonstrated to be a effective method for the analysis of preservatives in drinks. Furthermore, the method is simple, reproducible, envioronmentally friendly and inexpensive.


2013 ◽  
Vol 67 (2) ◽  
pp. 247-253 ◽  
Author(s):  
Zonghao Li ◽  
Gong Yu ◽  
Jun Song ◽  
Qi Wang ◽  
Mousheng Liu ◽  
...  

A new, simple and rapid method based on dispersive liquid–liquid microextraction (DLLME) was developed for extracting and preconcentrating copper (Cu), nickel (Ni), lead (Pb) and cadmium (Cd) in water samples prior to flame atomic absorption spectrometry (FAAS) analysis. 1-(2-thiazolylazo)-naphthol (TAN) was used as chelating reagents, and non-ionic surfactant Triton X-114 and CCl4 as disperser solvent and extraction solvent, respectively. Some influential factors relevant to DLLME, such as the concentration of TAN, type and volume of disperser and extraction solvent, pH and ultrasound time, were optimized. Under the optimal conditions, the calibration curve was linear in the range of 10–800 μg L−1 for Cu and Ni, 10–500 μg L−1 for Pb, and 10–1,000 μg L−1 for Cd, respectively. The limits of detection for the four metal ions were below 0.5 μg L−1, with the enhancement factors of 105, 66, 28 and 106 for Cu, Ni, Pb and Cd, respectively. The relative standard deviations (RSD, n = 6) were 2.6–4.1%. The proposed method was applied to determination of Cu, Ni, Pb and Cd in water samples and satisfactory relative recoveries (93.0–101.2%) were achieved.


2018 ◽  
Vol 53 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Nesrin Topaç ◽  
Cennet Karadaş ◽  
Derya Kara

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%.


2014 ◽  
Vol 881-883 ◽  
pp. 627-630 ◽  
Author(s):  
Jian Qi Sun ◽  
Fang Zeng ◽  
Xiao Feng Liu

This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of acrylates (methyl acrylate (MA), methyl methacrylate (MMA), butyl acrylate (BA)) in wastewater. For this purpose, dispersive liquid-liquid microextraction (DLLME) was applied as a sample preparation technique. The DLLME conditions such as the types and volume of extraction solvent, the types and volume of the disperser solvent, pH value and salt addition were studied and optimized. The method was linear in the ranges from 4.3×10-4 to 200.0 μg·mL-1 for abovementioned acrylates with R2≥ 0.9992. The DLLME procedure allowed efficient recovery of the investigated acrylates ranging between 81 % and 109 % with a relative standard deviation (RSD) ≤ 9.1 for the blank samples spiked with 10, 50 and 100 μg·mL-1 of acrylates, respectively. These results showed the potential of this technique for acrylates monitoring in wastewater samples. Furthermore, the investigated methods are simple, reproducible, and inexpensive.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Mostafa Bashiri Juybari ◽  
Ali Mehdinia ◽  
Ali Jabbari ◽  
Yadollah Yamini

In this study dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) followed by gas chromatography-electron capture detection (GC-ECD) was developed for determination of some pesticides in the water samples. Some important parameters, such as type and volumes of extraction and disperser solvent and salt effect on the extraction recovery of analytes from aqueous solution were investigated. Under the optimum conditions (extraction solvent: 1-undecanol, 15.0 μL; disperser solvent: acetone, 1.0 mL, and without salt addition), the preconcentration factors were obtained ranged from 802 to 915 for analytes. The linear ranges were from 0.05 to 100 μg L−1, and detection limits ranged from 0.05 to 0.008 μg L−1. The relative standard deviations (RSDs%, ) were between 3.2% and 6.7%. The proposed method was successfully applied to the determination of target analytes in the tap, sea, and river water samples, and satisfactory recoveries were obtained.


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