scholarly journals Stir bar-sorptive extraction, solid phase extraction and liquid-liquid extraction for levetiracetam determination in human plasma: comparing recovery rates

2015 ◽  
Vol 51 (2) ◽  
pp. 393-401 ◽  
Author(s):  
Priscila Freitas-Lima ◽  
Flavia Isaura Santi Ferreira ◽  
Carlo Bertucci ◽  
Veriano Alexandre Júnior ◽  
Sônia Aparecida Carvalho Dreossi ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Stir Bar Sorptive Extraction ◽  
Therapeutic Drug ◽  
Phase Extraction ◽  
Recovery Rates ◽  
Sorptive Extraction ◽  
Liquid Liquid Extraction ◽  
Relative Standard

<p>Levetiracetam (LEV), an antiepileptic drug (AED) with favorable pharmacokinetic profile, is increasingly being used in clinical practice, although information on its metabolism and disposition are still being generated. Therefore a simple, robust and fast liquid-liquid extraction (LLE) followed by high-performance liquid chromatography method is described that could be used for both pharmacokinetic and therapeutic drug monitoring (TDM) purposes. Moreover, recovery rates of LEV in plasma were compared among LLE, stir bar-sorptive extraction (SBSE), and solid-phase extraction (SPE). Solvent extraction with dichloromethane yielded a plasma residue free from usual interferences such as commonly co-prescribed AEDs, and recoveries around 90% (LLE), 60% (SPE) and 10% (SBSE). Separation was obtained using reverse phase Select B column with ultraviolet detection (235 nm). Mobile phase consisted of methanol:sodium acetate buffer 0.125 M pH 4.4 (20:80, v/v). The method was linear over a range of 2.8-220.0 µg mL<sup>-1</sup>. The intra- and inter-assay precision and accuracy were studied at three concentrations; relative standard deviation was less than 10%. The limit of quantification was 2.8 µg mL<sup>-1</sup>. This robust method was successfully applied to analyze plasma samples from patients with epilepsy and therefore might be used for pharmacokinetic and TDM purposes.</p>

scholarly journals Liquid-Liquid Extraction/Low-Temperature Purification (LLE/LTP) Followed by Dispersive Solid-Phase Extraction (d-SPE) Cleanup for Multiresidue Analysis in Palm Oil by LC-QTOF-MS

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Elham Sobhanzadeh ◽  
Keivan Nemati
Keyword(s):  
Low Temperature ◽  
Solid Phase Extraction ◽  
Palm Oil ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Phase Extraction ◽  
Dispersive Solid Phase Extraction ◽  
Ionization Source ◽  
Liquid Liquid Extraction ◽  
Relative Standard

An evaluation of the extraction of multiresidue pesticides from palm oil by liquid-liquid extraction/low-temperature purification (LLE/LTP) coupled with dispersive solid-phase extraction (d-SPE) as the cleanup procedure with the determination by liquid chromatography mass spectrometry using electrospray as the ionization source (LC-ESI-MS) was carried out. Optimization approaches were studied in terms of d-SPE to select efficiency of type and mass of adsorbents to obtain the highest recovery yield of pesticides and the lowest coextract fat residues in the final extract. The optimal conditions of d-SPE were obtained using 3 g of palm oil, 4 g anhydrous MgSO4, 150 mg of PSA, and 50 mg of GCB (PSA: GCB (3 : 1 w/w)). Recovery study was performed at three concentration levels (25, 50, and 100 ng kg−1), yielding recovery rates between 71.8 and 112.4% except diuron with relative standard deviations of 3.2–15.1%. Detection and quantification limits were lower than 2.7 and 8.2 ng kg−1, respectively. The proposed method was successfully applied to the analysis of market-purchased palm oil samples from two different brands collected in Kuala Lumpur, showing its potential applicability and revealing the presence of some of the target species in the ng g−1range.

Optimizing Pretreatment Methods and Application for Analysis of Geosmin and 2-Methylisobomeol in Drinking Water

2014 ◽  
Vol 700 ◽  
pp. 525-529 ◽  
Author(s):  
Wu Chang Song ◽  
Xing Li ◽  
Shao Hua Sun ◽  
Yan Ling Yang ◽  
Rui Bao Jia
Keyword(s):  
Drinking Water ◽  
Standard Deviation ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Phase Extraction ◽  
Solid Phase Micro Extraction ◽  
Liquid Liquid Extraction ◽  
Taste And Odor ◽  
Relative Standard

The different pretreatment methods for analysis of geosmin and 2-methylisobomeol by GC-MS in drinking water were systemically studied and applied, such as liquid-liquid extraction, solid phase extraction, and solid phase micro-extraction. The results show that solid phase extraction is the better one, which C18 and carbinol were adopted as filling and washing solvents. The relative standard deviation of SPE-GC-MS for analysis geosmin and 2-Methylisoborneol were 1.5% and 1.7%, the recovery rate were in the range of 98.8%~102.0% and 99.5%~104.0%, respectively. 2-methylisobomeol was the major taste and odor of a micro-polluted reservoir in later autumn to earlier winter, which was secreted by Planktothrix and Oscillatoria.

The Benefits and Limitations of Methods Development in Solid Phase Extraction: Mini Review

2014 ◽  
Vol 69 (4) ◽  
Author(s):  
Norfahana Abd-Talib ◽  
Siti Hamidah Mohd-Setapar ◽  
Aidee Kamal Khamis
Keyword(s):  
Sample Preparation ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Phase Extraction ◽  
Methods Development ◽  
Liquid Liquid Extraction ◽  
Target Analytes ◽  
Two Phases ◽  
Preparation Techniques

Over recent years, there has been an explosive growth of sample preparation techniques. Sample preparation is in most cases meant to be the isolation online or offline concentration of some components of interest or target analytes. Solid phase extraction (SPE) is a very popular technique nowadays in sample preparation. The principal is quite similar with liquid- liquid extraction (LLE) which involves partition of solutes between two phases. But, there are some differences between them and some benefits and limitations of difference types of SPE technique like presented in this paper.

Analytical Methodology for the Determination of Organochlorine Pesticides in Vegetation

2012 ◽  
Vol 95 (5) ◽  
pp. 1291-1310 ◽  
Author(s):  
Elisa Beceiro-González ◽  
María J González-Castro ◽  
Soledad Muniategui-Lorenzo ◽  
Purificación López-Mahía ◽  
Darío Prada-Rodríguez
Keyword(s):  
Sample Preparation ◽  
Solid Phase Extraction ◽  
Organochlorine Pesticides ◽  
Pesticide Residues ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Stir Bar Sorptive Extraction ◽  
Phase Extraction ◽  
Chromatographic Techniques ◽  
Wide Range

Abstract Due to the extensive use of organochlorine pesticides (OCPs) for agricultural purposes and their high persistence and low biodegradability, they have become an important group of contaminants. Detection and quantification of pesticide residues in food, particularly fruits and vegetables, is of growing concern for producers, consumers, and governments. The most widely used pretreatment for the extraction of pesticides in plants is based on solvent extraction liquid-solid extraction (LSE). LSE can be carried out using Soxhlet, shake-flask, homogenization, sonication, and, more recently, microwave-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction. Furthermore, new analytical procedures using the extraction with sorbents, such as solid-phase micro-extraction, stir bar sorptive extraction, and matrix solid-phase dispersion, have also been used. On the other hand, a wide range of cleanup methods (liquid–liquid extraction, solid-phase extraction, gel permeation chromatography, and dispersive solid-phase extraction; and chromatographic techniques with electron capture detector and mass spectrometry detector; and HPLC with a ultraviolet detector are reported in the literature. This article reviews the applicability, advantages, and disadvantages of various sample preparation techniques (traditional and new techniques) for the analysis of OCPs in different plants and plant materials. It covers more than 15 years of published methods in which pesticide residues have been determined in a wide range of vegetation samples (fruits, horticultural samples, medicinal plants, tree leaves, etc.) by the use of chromatographic techniques after various sample preparation steps. A great number of applications in different plant material are provided. To the best of the authors' knowledge, previously published reviews have not covered as wide and exhaustive range of vegetation matrixes as presented here. A summary of pesticide levels cited in the literature is included.

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