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.

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 A Vortex-Assisted Dispersive Liquid-Liquid Microextraction Followed by UPLC-MS/MS for Simultaneous Determination of Pesticides and Aflatoxins in Herbal Tea

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1029 ◽  
Author(s):  
Rui Zhang ◽  
Zhen-Chao Tan ◽  
Ke-Cheng Huang ◽  
Yan Wen ◽  
Xiang-Ying Li ◽  
...  
Keyword(s):  
Organophosphorus Pesticides ◽  
Optimum Conditions ◽  
Herbal Tea ◽  
Surface Design ◽  
Extraction Solvent ◽  
The Mean ◽  
Dispersive Liquid Liquid Microextraction ◽  
Pesticides Residue ◽  
Liquid Microextraction

A method for detecting the organophosphorus pesticides residue and aflatoxins in China herbal tea has been developed by UPLC-MS/MS coupled with vortex-assisted dispersive liquid-liquid microextraction (DLLME). The extraction conditions for vortex-assisted DLLME extraction were optimized using single-factor experiments and response surface design. The optimum conditions for the experiment were the pH 5.1, 347 µL of chloroform (extraction solvent) and 1614 µL of acetonitrile (dispersive solvent). Under the optimum conditions, the targets were good linearity in the range of 0.1 µg/L–25 µg/L and the correlation coefficient above 0.9998. The mean recoveries of all analytes were in the ranged from 70.06%–115.65% with RSDs below 8.54%. The detection limits were in the range of 0.001 µg/L–0.01µg/L. The proposed method is a fast and effective sample preparation with good enrichment and extraction efficiency, which can simultaneously detect pesticides and aflatoxins in China herbal tea.

Dispersive Liquid-Liquid Microextraction Based on Ionic Liquid and Spectrophotometric Determination of Bilirubin in Biological Samples

2020 ◽  
Vol 16 (5) ◽  
pp. 652-659
Author(s):  
Asiye A. Avan ◽  
Hayati Filik
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Biological Samples ◽  
Urine Samples ◽  
Spectrophotometric Detection ◽  
Full Color ◽  
Dispersive Liquid Liquid Microextraction ◽  
Urine And Serum ◽  
Liquid Microextraction

Background: An Ionic Liquid-based based Dispersive Liquid-Liquid Microextraction (IL-DLLME) method was not applied to preconcentration and determination of bilirubin. Ionic Liquids (ILs) are new chemical compounds. In recent years, Ionic Liquids (ILs) have been employed as alternative solvents to toxic organic solvents. Due to these perfect properties, ILs have already been applied in many analytical extraction processes, presenting high extraction yield and selectivity for analytes. Methods: In this study, IL-DLLME was applied to biological samples (urine and serum) for the spectrophotometric detection of bilirubin. For bilirubin analysis, the full-color development was based on the reaction with periodate in the presence of hydrochloric acid. The high affinity of bilirubin for the ionic liquid phase gave extraction percentages above 98% in 0.3 M HCl solution. Results: Several IL-extraction parameters were optimized and room temperature ionic liquid 1-butyl- 1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and ethanol were used as extraction and disperser solution. The linear range was found in the range of 0.5-6.0 μM (0.3-3.5 μg mL-1) and the limits of detection of the proposed method was 0.5 μM (0.3 μg mL-1). The proposed method was applied for the preconcentration and separation of trace bilirubin in real urine samples. Also, the recoveries for bilirubin in spiked biological samples (urine and serum) were found to be acceptable, between 95-102%. Conclusion: The proposed IL-DLLMEapproach was employed for the enrichment and determination of trace levels of bilirubin in urine samples using NaIO4 as an oxidizing agent and Uv-vis spectrophotometric detection. The periodate oxidation of bilirubin is rapid, effective, selective, and simple to perform. The method contains only HCl, NaOI4, and an anionic surfactant. The method may be useful for economizing in the consumption of reagents in bilirubin determining. The IL-DLLMEmethod ensures a high yield and has a low toxicity no skin sensitization, no mutagenicity and no ecotoxicity in an aquatic environment since only very low quantities of an IL is required. For full-color formation, no any extra auxiliary reagents are required. Besides, the IL-DLLME technique uses a low-cost instrument such as Uv-vis which is present in most of the medical laboratories.

Determination of UV-327 and its metabolites in human urine using dispersive liquid-liquid microextraction and gas chromatography-tandem mass spectrometry

2021 ◽  
Vol 13 (35) ◽  
pp. 3978-3986
Author(s):  
Corinna Fischer ◽  
Thomas Göen
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Tandem Mass Spectrometry ◽  
Human Urine ◽  
Tandem Mass ◽  
Extraction Solvent ◽  
Chromatography Tandem Mass Spectrometry ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

A method is presented for the extraction of the UV stabilizer UV-327 and its metabolites from urine with acetonitrile (disperser solvent) and chloroform (extraction solvent), followed by instrumental analysis of the trimethylsilylated analytes.

scholarly journals Analytical Scheme for Simultaneous Determination of Phthalates and Bisphenol A in Honey Samples Based on Dispersive Liquid–Liquid Microextraction Followed by GC-IT/MS. Effect of the Thermal Stress on PAE/BP-A Levels

2020 ◽  
Vol 3 (1) ◽  
pp. 23 ◽  
Author(s):  
Ivan Notardonato ◽  
Sergio Passarella ◽  
Giuseppe Ianiri ◽  
Cristina Di Fiore ◽  
Mario Vincenzo Russo ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Simultaneous Determination ◽  
Thermal Stresses ◽  
Ion Trap ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Analytical Scheme ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

In this paper, an analytical protocol was developed for the simultaneous determination of phthalates (di-methyl phthalate DMP, di-ethyl phthalate DEP, di-isobutyl phthalate DiBP, di-n-butyl phthalate DBP, bis-(2-ethylhexyl) phthalate DEHP, di-n-octyl phthalate DNOP) and bisphenol A (BPA). The extraction technique used was the ultrasound vortex assisted dispersive liquid–liquid microextraction (UVA-DLLME). The method involves analyte extraction using 75 µL of benzene and subsequent analysis by gas chromatography combined with ion trap mass spectrometry (GC-IT/MS). The method is sensitive, reliable, and reproducible with a limit of detection (LOD) below 13 ng g−1 and limit of quantification (LOQ) below 22 ng g−1 and the intra- and inter-day errors below 7.2 and 9.3, respectively. The method developed and validated was applied to six honey samples (i.e., four single-use commercial ones and two home-made ones. Some phthalates were found in the samples at concentrations below the specific migration limits (SMLs). Furthermore, the commercial samples were subjected to two different thermal stresses (24 h and 48 h at 40 °C) for evidence of the release of plastic from the containers. An increase in the phthalate concentrations was observed, especially during the first phase of the shock, but the levels were still within the limits of the regulations.

scholarly journals Dispersive liquid-liquid microextraction and liquid chromatographic determination of pentachlorophenol in water

2009 ◽  
Vol 7 (3) ◽  
pp. 369-374 ◽  
Author(s):  
Khalil Farhadi ◽  
Mir Farajzadeh ◽  
Amir Matin ◽  
Paria Hashemi
Keyword(s):  
Water Samples ◽  
Dynamic Range ◽  
Chromatographic Determination ◽  
Extraction Solvent ◽  
Wide Linear Dynamic Range ◽  
Liquid Chromatographic Determination ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Chromatographic ◽  
Liquid Microextraction

AbstractA simple and sensitive dispersive liquid-liquid microextraction method for extraction and preconcentration of pentachlorophenol (PCP) in water samples is presented. After adjusting the sample pH to 3, extraction was performed in the presence of 1% W/V sodium chloride by injecting 1 mL acetone as disperser solvent containing 15 μL tetrachloroethylene as extraction solvent. The proposed DLLME method was followed by HPLC-DAD for determination of PCP. It has good linearity (0.994) with wide linear dynamic range (0.1–1000 μg L−1) and low detection limit (0.03 μg L−1), which makes it suitable for determination of PCP in water samples.

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%.

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