Liquid-liquid extraction and ultrafiltration based sample preparation technique for Q-TOF LC/MS analysis of non-polar metabolites in human plasma samples

Background:Uremia is the outcome of the remaining of nitrogenous waste products that are normally removed by the kidneys. Para-cresol (4-methylphenol) can be regarded as a proteinbound uremic toxin. The p-cresol determination in sera is necessary since it is a marker of cardiovascular risk and overall mortality in hemodialysis patients. Among the reported methods, chromatographic ones especially HPLC techniques due to the high sensitivity, selectivity and reproducibility have been extensively exploited in analysis of p-cresol in complex mixtures. However, an appropriate sample preparation prior to analysis is necessary for obtaining accurate and precise results.Methods:In this study, the appropriate precipitating agent for p-cresol determination in plasma samples was investigated. Then, in situ surfactant-based solid phase microextraction followed by HPLCFL detection was developed and validated for the quantification of p-cresol in plasma samples.Results:According to the results, HCl/heat precipitation method was used for p-cresol microextraction from from plasma samples. In situ surfactant-based solid phase microextraction using cetyltrimethylammonium bromide as extraction medium was proposed for pretreatment of plasma samples prior to analysis. The separation was achieved by isocratic elution with sodium acetate buffer (pH 3.8) and acetonitrile (20:80, v/v). Linearity was found to be acceptable over the concentration ranges of 0.5 to 8 μg mL-1 with the limit of detection and quantification of 0.324 and 0.422 μg mL-1, respectively. The variations for intra-day and inter-day precisions were both less than 8.2% and the extraction recoveries were more than 97%.Conclusion:A validated ISS-SPME followed by HPLC-FL detection reported to determine the total p-cresol concentration of human plasma samples. The traditional liquid-liquid extraction techniques are normally time consuming and require the use of large amounts of toxic organic solvents. In addition, the evaporation of extraction solvent and dissolving the analyte in the mobile phase is commonly used before HPLC analysis. Such a requirement makes the sample preparation process even more tedious and time consuming. ISS-SPME that is the developed ISS-SPE in micro scale, is a simple, rapid and effective sample preparation technique that is appropriate for HPLC-FL analysis.

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Development of an UPLC-MS/MS Method for Quantitative Analysis of Clotrimazole in Human Plasma Samples

Separations ◽

10.3390/separations7040062 ◽

2020 ◽

Vol 7 (4) ◽

pp. 62

Author(s):

Lucia Lisi ◽

Gabriella Maria Pia Ciotti ◽

Pierluigi Navarra

Keyword(s):

Human Plasma ◽

Plasma Concentrations ◽

Correlation Coefficients ◽

Ultra Performance Liquid Chromatography ◽

Plasma Samples ◽

Nominal Concentration ◽

Liquid Liquid Extraction ◽

Human Plasma Samples ◽

Liquid Chromatography Tandem Mass ◽

Intravaginal Administration

An ultra-performance liquid chromatography-tandem mass spectrometry method was developed for the quantification of clotrimazole (CTZ) plasma levels after intravaginal administration of the drug given at approved dosages. Plasma samples were extracted by liquid–liquid extraction and a single chromatographic run could be completed within about 2 min. The method was linear over the investigated range (0.488–250 ng/mL) with all the correlation coefficients, R2, greater than 0.9903. All data were in the range of ±15.0% with respect to the nominal concentration for high QC and medium QC, and in the range ±20% with respect to the nominal concentration for low QC. This rapid and sensitive method was validated and could be applied to human plasma samples from a healthy volunteer, showing that the assay is able to detect plasma concentrations of CTZ in the range of those found after the administration of the drug at approved dosages in the clinical setting.

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Determination of verapamil and norverapamil in human plasma by liquid chromatography: Comparison between a liquid—liquid extraction procedure and an automated liquid—solid extraction method for sample preparation

Journal of Pharmaceutical and Biomedical Analysis ◽

10.1016/0731-7085(91)80102-f ◽

1992 ◽

Vol 10 (10-12) ◽

pp. 937-942 ◽

Cited By ~ 20

Author(s):

Ph. Hubert ◽

P. Chiap ◽

A. Ceccato ◽

I. Bechet ◽

R. Sibenaler-Dechamps ◽

...

Keyword(s):

Liquid Chromatography ◽

Sample Preparation ◽

Human Plasma ◽

Extraction Method ◽

Extraction Procedure ◽

Liquid Extraction ◽

Solid Extraction ◽

Liquid Liquid Extraction

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Comparison of Different Sample Preparation Techniques for Untargeted Metabolomics utilizing Q-TOF LC/MS and MetaboAnalyst 4.0

Current Metabolomics and Systems Biology ◽

10.2174/2666338408999200614155440 ◽

2020 ◽

Vol 08 ◽

Author(s):

Ozan Kaplan ◽

Engin Koçak ◽

Mustafa Çelebier

Keyword(s):

Sample Preparation ◽

Solid Phase Extraction ◽

Solid Phase ◽

Phase Extraction ◽

Preparation Technique ◽

Sample Preparation Technique ◽

Ms Analysis ◽

Ionization Mode ◽

Human Blood Samples ◽

Preparation Techniques

Background: Profiling the whole metabolome with a single injection is not an easy process because the chemical and physical properties of metabolites are totally different within each other and the analytical methodologies and datamining procedures need lots of effort to make such an approach for real. This reality leads researchers to select an already applied methodology for metabolite profiling and analyze the samples through identical techniques. Objective: In this study, it was focused whether the sample preparation techniques on human blood samples prior to QTOF LC/MS analysis affect the number of detectable peaks and to analyze the matched metabolites of these peaks. The results were compared within each other. Method: Precipitation of proteins with methanol, ultrafiltration (Amicon® Ultra 3 kDa 0.5 mL Centrifugal Filters), liquidphase extraction (EXtrelut® NT 3 cartridges) and solid-phase extraction (Supelco HybridSPE®-Phospholipid Cartridge) were used for sample preparation on commercial pooled plasmas samples. C18 column (Agilent Zorbax 1.8 μM, 50 x 2.1 mm) was used as the chromatography column. Q-TOF LC/MS analysis was performed on positive ionization mode. XCMS and MetaboAnalyst 4.0 - MS Peaks to Pathways utility were used to evaluate the raw data. Results: Although the number of detected peaks through precipitation with methanol was the highest one (624 peaks), the detected peaks observed through ultrafiltration sample preparation technique matched with the highest number of metabolite peaks (151 metabolites). The number of the matched peaks with metabolites on liquid phase extraction (81 metabolites) was higher than the ones for solid phase extraction (29 metabolites). Conclusion: The results in this study may provide a novel perspective to analytical chemists working with clinicians to select their sample preparation technique prior to Q-TOF LC/MS based untargeted metabolomic approaches.

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