scholarly journals Control of matrix effects in the analysis of urinary F2-isoprostanes using novel multidimensional solid-phase extraction and LC-MS/MS

2007 ◽  
Vol 48 (3) ◽  
pp. 733-744 ◽  
Author(s):  
Bo Zhang ◽  
Keijiro Saku
Keyword(s):  
Solid Phase Extraction ◽  
Matrix Effects ◽  
Solid Phase ◽  
Phase Extraction

A solid-phase extraction method that eliminates matrix effects of complex pulp mill effluents for the analysis of lipophilic wood extractives

2020 ◽  
Vol 35 (4) ◽  
pp. 577-588
Author(s):  
Sebastian España Orozco ◽  
Philipp Zeitlinger ◽  
Karin Fackler ◽  
Robert H. Bischof ◽  
Antje Potthast
Keyword(s):  
Solid Phase Extraction ◽  
Matrix Effects ◽  
Solid Phase ◽  
Internal Standard ◽  
Pulp Mill ◽  
Phase Extraction ◽  
Wood Extractives ◽  
Wood Extractive ◽  
Pulp Mill Effluents ◽  
The Impact

AbstractThe extraction of lipophilic wood extractives from pulp and paper process waters proves to be a challenging task, due to harsh and alternating process and sample conditions. This study has determined the potential use of polymeric sorbents for solid-phase extraction (SPE) and compared to classical silica-based reversed-phase packed columns, with polymeric hydrophilic-lipophilic balanced (HLB) cartridges being the sorbent with the most potential. Recovery functions were obtained with an internal standard mixture representative for the main lipophilic wood extractive groups, which are fatty acids and alcohols, sterols, sterol esters and triglycerides. The impact of pH, sample volume and sample matrix, expressed as TOC and cations, on the retention behavior of lipophilic extractives during SPE of industrial samples were determined with polymeric HLB sorbent. High variations in the composition of pulp mill matrices led to different optimal extraction conditions. Thus, a new SPE protocol was developed, which bypasses matrix interferences and omits the loss of analytes due to sample preparation. The method is applicable to different pulp mill effluents with large discrepancies in pH and sample matrices, resulting in recoveries >90 % with RSD <5 % for all lipophilic wood extractives.

scholarly journals Sample Preparation and Extraction in Small Sample Volumes Suitable for Pediatric Clinical Studies: Challenges, Advances, and Experiences of a Bioanalytical HPLC-MS/MS Method Validation Using Enalapril and Enalaprilat

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Bjoern B. Burckhardt ◽  
Stephanie Laeer
Keyword(s):  
Sample Preparation ◽  
Solid Phase Extraction ◽  
Method Development ◽  
Matrix Effects ◽  
Solid Phase ◽  
Scale Up ◽  
Small Sample ◽  
Positive Pressure ◽  
Phase Extraction ◽  
Bioanalytical Method

In USA and Europe, medicines agencies force the development of child-appropriate medications and intend to increase the availability of information on the pediatric use. This asks for bioanalytical methods which are able to deal with small sample volumes as the trial-related blood lost is very restricted in children. Broadly used HPLC-MS/MS, being able to cope with small volumes, is susceptible to matrix effects. The latter restrains the precise drug quantification through, for example, causing signal suppression. Sophisticated sample preparation and purification utilizing solid-phase extraction was applied to reduce and control matrix effects. A scale-up from vacuum manifold to positive pressure manifold was conducted to meet the demands of high-throughput within a clinical setting. Faced challenges, advances, and experiences in solid-phase extraction are exemplarily presented on the basis of the bioanalytical method development and validation of low-volume samples (50 μL serum). Enalapril, enalaprilat, and benazepril served as sample drugs. The applied sample preparation and extraction successfully reduced the absolute and relative matrix effect to comply with international guidelines. Recoveries ranged from 77 to 104% for enalapril and from 93 to 118% for enalaprilat. The bioanalytical method comprising sample extraction by solid-phase extraction was fully validated according to FDA and EMA bioanalytical guidelines and was used in a Phase I study in 24 volunteers.

scholarly journals Cannabinoids in Exhaled Breath following Controlled Administration of Smoked Cannabis

2013 ◽  
Vol 59 (12) ◽  
pp. 1780-1789 ◽  
Author(s):  
Sarah K Himes ◽  
Karl B Scheidweiler ◽  
Olof Beck ◽  
David A Gorelick ◽  
Nathalie A Desrosiers ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Time Course ◽  
Matrix Effects ◽  
Solid Phase ◽  
Driving Under The Influence ◽  
Phase Extraction ◽  
Exhaled Breath ◽  
C Storage ◽  
Before And After ◽  
Occasional Smoker

BACKGROUND Δ9-Tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), and cannabinol (CBN) were measured in breath following controlled cannabis smoking to characterize the time course and windows of detection of breath cannabinoids. METHODS Exhaled breath was collected from chronic (≥4 times per week) and occasional (&lt;twice per week) smokers before and after smoking a 6.8% THC cigarette. Sample analysis included methanol extraction from breath pads, solid-phase extraction, and liquid chromatography–tandem mass spectrometry quantification. RESULTS THC was the major cannabinoid in breath; no sample contained THCCOOH and only 1 contained CBN. Among chronic smokers (n = 13), all breath samples were positive for THC at 0.89 h, 76.9% at 1.38 h, and 53.8% at 2.38 h, and only 1 sample was positive at 4.2 h after smoking. Among occasional smokers (n = 11), 90.9% of breath samples were THC-positive at 0.95 h and 63.6% at 1.49 h. One occasional smoker had no detectable THC. Analyte recovery from breath pads by methanolic extraction was 84.2%–97.4%. Limits of quantification were 50 pg/pad for THC and CBN and 100 pg/pad for THCCOOH. Solid-phase extraction efficiency was 46.6%–52.1% (THC) and 76.3%–83.8% (THCCOOH, CBN). Matrix effects were −34.6% to 12.3%. Cannabinoids fortified onto breath pads were stable (≤18.2% concentration change) for 8 h at room temperature and −20°C storage for 6 months. CONCLUSIONS Breath may offer an alternative matrix for identifying recent driving under the influence of cannabis, but currently sensitivity is limited to a short detection window (0.5–2 h).

Molecularly Imprinted Solid-Phase Extraction for Chlorpyrifos Determination in Water Samples

2010 ◽  
Vol 113-116 ◽  
pp. 947-951 ◽  
Author(s):  
Jun Liu ◽  
Ming Yang ◽  
Lu Feng Huai
Keyword(s):  
Solid Phase Extraction ◽  
Water Samples ◽  
Matrix Effects ◽  
Solid Phase ◽  
Final Analysis ◽  
Sewage Water ◽  
Phase Extraction ◽  
Simple Method ◽  
Molecularly Imprinted ◽  
The Matrix

The determination of chlorpyrifos at low ngL-1 levels in wastewater requires highly selective and sensitive analytical procedures. The removal of matrix components during sample preparation results in significant benefits towards reducing the matrix effects during GC analysis. Therefore this work describes a simple method to enrich and clean up chlorpyrifos from sewage water using molecularly imprinted solid phase extraction (MISPE). Final analysis was performed by gas chromatography. The performance of this method has been evaluated in water samples in terms of recovery, precision, and method quantification limit. Recovery for chlorpyrifos ranged between 99 and 105% with RSD values below 7.9%. The performance of the method was further emphasized by the study of different water samples. In these samples, chlorpyrifos were detected in concentration above method quantification limits ranging from 50 to 3000 ngL-1.

scholarly journals Use of Magnesium Silicate as a New Type of Adsorbent for Dispersive Solid-Phase Extraction Cleanup of the Quick, Cheap, Effective, Rugged, and Safe Method for Pesticides During Analysis of Lager Beer by Gas Chromatography-Tandem Mass Spectrometry

2019 ◽  
Vol 102 (2) ◽  
pp. 619-624 ◽  
Author(s):  
Sandro Navickiene ◽  
Luis Fabrício Santana Santos ◽  
Alexandre dos Reis Silva
Keyword(s):  
Solid Phase Extraction ◽  
Matrix Effects ◽  
Solid Phase ◽  
Magnesium Silicate ◽  
Phase Extraction ◽  
Dispersive Solid Phase Extraction ◽  
Important Approach ◽  
Efficient Alternative ◽  
Lager Beer ◽  
Concentration Levels

Abstract Background: Pesticides are applied for pest control during the production of cereal grains used in beer production. Given the risks for consumers, it is important to analyze the pesticide residues. Objective: Quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methods are very effective, and improvement inthe cleanup step is an important approach. Methods: Primary secondary amine (PSA) andmagnesium silicate were evaluated for dispersive-solid-phase extraction (d-SPE) cleanup step in extracts provided by the QuEChERS method in combination with GC-tandem MS for the determination of acetamiprid, terburfos, alachlor, ametryn, atrazine, azoxystrobin, carbofuran, carbosulfan, cypermethrin, deltamethrin, difenoconazole, esfenvalerate, flutriafol,thiamethoxam, and parathion-methyl in lager beer. Results: The amount of 50 mg of magnesium silicate was suitable for cleaning up beer extract as an alternative d-SPE material to PSA. Themethod was validated using beer fortified with pesticides at three concentration levels (0.002, 0.01, and 0.1 μg/mL). Average recoveries ranged from 70 to 123%, with RSDs between 0.3 and 10.5 %. Matrix effects were observed by comparing the slope of matrix-matched standard calibration with that of solvent. The method provided good linearity at the concentration levels of 0.001–2.5 μg/mL. Detection limits ranged from 0.0001 to 0.0007 μg/mL and quantification limits ranged from 0.001 to 0.006 μg/mL. The method was applied to nine beer brands. Conclusions: Results showed that magnesium silicate is an efficient alternative cleanup material to reduce analysiscosts while maintaining the method reliability and accuracy. Highlights: Magnesium silicate was effective as adsorbent for d-SPE step inthe analysis of pesticides in beer.

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