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.

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.

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 Novel Chromatographic Separation and Carbon Solid-Phase Extraction of Acetanilide Herbicide Degradation Products

2002 ◽  
Vol 85 (6) ◽  
pp. 1331-1337 ◽  
Author(s):  
Jody A Shoemaker
Keyword(s):  
Drinking Water ◽  
Solid Phase Extraction ◽  
Chromatographic Separation ◽  
Solid Phase ◽  
Degradation Products ◽  
The United States ◽  
Negative Ion ◽  
Phase Extraction ◽  
Herbicide Degradation ◽  
Relative Standard

Abstract One acetamide and 5 acetanilide herbicides are currently registered for use in the United States. Over the past several years, ethanesulfonic acid (ESA) and oxanilic acid (OA) degradation products of these acetanilide/acetamide herbicides have been found in U.S. ground waters and surface waters. Alachlor ESA and other acetanilide degradation products are listed on the U.S. Environmental Protection Agency's (EPA) 1998 Drinking Water Contaminant Candidate List. Consequently, EPA is interested in obtaining national occurrence data for these contaminants in drinking water. EPA currently does not have a method for determining these acetanilide degradation products in drinking water; therefore, a research method is being developed using liquid chromatography/negative ion electrospray/mass spectrometry with solid-phase extraction (SPE). A novel chromatographic separation of the acetochlor/alachlor ESA and OA structural isomers was developed which uses an ammonium acetate–methanol gradient combined with heating the analytical column to 70°C. Twelve acetanilide degradates were extracted by SPE from 100 mL water samples using carbon cartridges with mean recoveries &gt;90% and relative standard deviations ≤16%.

scholarly journals Multiresidue Determination of Pesticides in Drinking and Related Waters by Solid-Phase Extraction and Liquid Chromatography with Ultraviolet Detection: Interlaboratory Study

2002 ◽  
Vol 85 (2) ◽  
pp. 375-383 ◽  
Author(s):  
François van Hoof ◽  
Peter van Wiele ◽  
Françoise Acobas ◽  
Jean-Luc Guinamant ◽  
Auguste Bruchet ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Solid Phase Extraction ◽  
Relative Standard Deviation ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Tap Water ◽  
Phase Extraction ◽  
Relative Standard ◽  
Styrene Divinylbenzene

Abstract As part of a project funded by the European Commission (EC) for the development and evaluation of multiresidue methods for analysis of drinking and related waters, 17 European laboratories evaluated a method using styrene–divinylbenzene copolymer solid-phase extraction followed by liquid chromatography with diode array detection. The main aim of the study was to evaluate whether the method meets the requirements of EC Drinking Water Directive 98/83 in terms of accuracy, precision, and detection limit for 21 pesticides according to the following requirements: limit of detection, ≤0.025 μg/L; accuracy expressed as recovery, between 75 and 125%; and precision expressed as repeatability relative standard deviation of the method, &lt;12.5%, and as reproducibility relative standard deviation of the method, &lt;25%. Analyses for unknown concentrations were performed with commercial bottled and tap waters. All laboratories were able to achieve detection limits of 0.01 μg/L for all pesticides except pirimicarb (0.02 μg/L). The criteria for repeatability were met for all compounds. Terbutryn in bottled water and carbendazim in tap water did not meet the criteria for reproducibility. In terms of accuracy, the method met the requirements for all pesticides in both matrixes, except for metamitron. However, several compounds (linuron, terbutryn, propazine, metobromuron, and isoproturon) showed recoveries slightly below 75%.

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