scholarly journals Extraction Properties of 4-Tetra(hydroxyphenyl)BTPhen in Liquid-Liquid Extraction Systems with Cyclohexanone/Octanol or in a Solid-Phase Extraction System

Heterocycles ◽  
2020 ◽  
Vol 101 (1) ◽  
pp. 209
Author(s):  
Laurence M. Harwood ◽  
Jan John ◽  
Ashfaq Afsar ◽  
Jasraj S. Babra ◽  
Petr Distler ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Extraction System ◽  
Phase Extraction ◽  
Liquid Liquid Extraction ◽  
Extraction Properties

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.

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>

Efficiency evaluation of extraction methods of selected benzodiazepine derivatives from human serum and whole blood and the reactivity phenomenon in immunoassay for benzodiazepines

2016 ◽  
Vol 52 (2) ◽  
pp. 107-114
Author(s):  
Barbara Potocka-Banaś ◽  
Teresa Dembińska ◽  
Krzysztof Borowiak
Keyword(s):  
Solid Phase Extraction ◽  
Whole Blood ◽  
Solid Phase ◽  
Extraction Methods ◽  
Cross Reactivity ◽  
Liquid Extraction ◽  
Array Detector ◽  
Phase Extraction ◽  
Liquid Liquid Extraction ◽  
Benzodiazepine Derivatives

The aim of the study was to compare efficiency of various extraction methods of benzodiazepine derivatives: diazepam, estazolam, flunitrazepam and nitrazepam. The study compared the recovery of benzodiazepines isolated from biological material (blood and human blood serum) using liquid-liquid extraction and solid-phase extraction. The efficiency of each extraction was evaluated using high-performance liquid chromatography with diode array detector. In addition, benzodiazepines immunoassay reactivity was estimated. The following methods of extraction were used: liquid-liquid extraction (a classical liquid-liquid extraction and microextraction), solid- -phase extraction (Baker’s columns and United Chemical Technologies’ (UTC columns). The reactivity was evaluated using V-Twin System with EMIT technology by Siemens. The results showed that the lowest recovery (nitrazepam – 16%, diazepam – 23%, flunitrazepam – 28%, estazolam – 37%) was obtained using liquid-liquid microextraction of whole blood and the highest recovery was obtained in solid-phase extraction of whole blood using United Chemical Technologies’ columns (nitrazepam – 86%, diazepam – 89%, estazolam – 91%, flunitrazepam – 94%). The lowest recovery in classical liquid-liquid extraction was obtained for diazepam isolated from whole blood (36%), and the highest – for flunitrazepam isolated from serum (74%). Solid-phase extraction with Baker’s columns was successful only in case of drugs isolation from serum and the recovery range from 57% to 89% for flunitrazepam. The results indicated higher efficiency of solid-phase extraction, especially with use of columns specific for the extraction of benzodiazepines. The immunoassay analysis showed a decreased reactivity of the tested benzodiazepine derivatives on the reagent used for the EMIT assay. Comparative analysis of the recovery efficiency of selected benzodiazepine derivatives led to the conclusion that use of solid-phase extraction should be considered more often in routine toxicological analysis. The knowledge of benzodiazepine derivatives cross-reactivity in immunoassay method is essential for correct interpretation of obtained results.

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