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Aim: We proposed a rapid and high quality method to determine α-tocopherol (α-T) in different biopharmaceutical samples using liquid chromatography-diode array detector on-line ESI-MS/MS., Materials & Methods: A working standard solution of α-T and internal standard, phenyl-5,7-dimethyl-d6-α-tocopherol, were used for optimization and validation of the method. Levels of α-T in nanoemulsions, serum and plasma samples were evaluated., Results & Conclusion: Precision (1% for retention time, 5% for peak area and 3% for relative peak area), linearity range (among 0.625-20.0 μg ml -1 ), LOD and LOQ, accuracy and matrix effect were studied. The validated chromatographic method is presented as valuable analytical tool for the determination of α-tocopherol in loaded drug delivery systems and in biodistribution levels in blood samples.

This work is about improvement of a maceration method in order to achieve a green process for the enrichment of virgin olive oil (VOO) with natural antioxidants, specifically from oregano leaves. This goal was accomplished after evaluating different mechanical methods, i.e. magnetic stirring, sonication, vertical stirring and sonication in combination with vertical stirring, for promoting the extraction of the antioxidants from oregano. The results obtained indicated that the best extraction procedure was vertical stirring at 1000 r.p.m. for 3 h. Therefore, these conditions were selected to enrich VOO with phenolic acids (mainly rosmarinic acid) and endogenous antioxidants (o-coumaric and vanillic acids), and further determine their stability at room temperature or under temperature stress (50°C) during 45 days. Quantitative analysis of rosmarinic, o-coumaric and vanillic acids was carried out by an off-line, solid phase extraction, capillary zone, electrophoresis method combined with diode-array detector (SPE-CE-DAD)., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Many recent papers and reviews have confirmed the powerful coupling between CE and MS due to efficient and selective separation in combination with selective detection allowing detailed characterization of many biomolecules. It is known that CE-MS is an increasingly used and sought after technique for analysis in different fields such as environmental science, food analysis, biotechnology, pharmaceutical analysis, biomedical science, forensic science, toxicology, and genetic analysis. CE-MS is particularly used in bio-omic applications (proteomic, metabolomic, and also genomic applications) for the determination of biomarkers, disease diagnosis, and therapeutic treatment monitoring. Biomarker qualification, clinical proteomics, and its implementation in routine clinical analysis have certain limitations associated with reproducibility and analytical robustness. However, CE-MS has been successfully used in numerous clinical applications in recent years when compared with other platforms. The main advantage lies in the availability of large comparable datasets that were all obtained by using the same procedure for sample preparation, analysis, and subsequent data evaluation. The scope of this review is to discuss the performance of CE-MS as a platform for bio-omics analysis and target-based applications focusing on quadrupole (Q), IT, and TOF analyzers, and the types of bioapplications that apply to the particular analyzers. Papers and reviews that were published in 2012 and 2013 with relevant CE-MS applications are considered in this review., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report a novel method for the simultaneous determination of omeprazole and their main metabolites (omeprazole sulphide, omeprazole sulphone and 5-hydroxy omeprazole) in human urine samples. For this purpose, two new capillary electrophoresis (CE) methods were developed for the simultaneous determination of target compounds, using initially diode-array for optical detection and electrospray ionization-mass spectrometry (ESI-MS) for metabolites identification and identity confirmation. A new metabolite (5-hydroxysulphide omeprazole) was identified by electrospray ionization multi-stage mass spectrometry (ESI-MS2) fragment which was then used to support the proposed chemical structure. Pharmacokinetic results using CE method were compared with those obtained when a HPLC method was used. Equivalent pharmacokinetics profiles resulted when any analytical methods were carried out., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The enrichment of virgin olive oil (VOO) with natural antioxidants contained in various herbs (rosemary, thyme and oregano) was studied. Three different enrichment procedures were used for the solid-liquid extraction of antioxidants present in the herbs to VOO. One involved simply bringing the herbs into contact with the VOO for 190 days; another keeping the herb-VOO mixture under stirring at room temperature (25°C) for 11 days; and the third stirring at temperatures above room level (35-40°C). The efficiency of each procedure was assessed by using a reproducible, efficient, reliable analytical capillary zone electrophoresis (CZE) method to separate and determine selected phenolic compounds (rosmarinic and caffeic acid) in the oil. Prior to electrophoretic separation, the studied antioxidants were isolated from the VOO matrix by using an optimised preconcentration procedure based on solid phase extraction (SPE). The CZE method was optimised and validated., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

A ThermoFinnigan sheath liquid flow capillary electrophoresis-mass spectrometry system designed for coupling via a co-axial interface was coupled through an adapted via an alternative, commercially available interface for orthogonal sampling. The affordable, reversible structural alterations made in the commercial LC-MS interface resulted in improved analytical performance. The results of a conventional capillary electrophoresis (CE) method using a commercial co-axial source to determine antioxidant phenolic acids present in virgin olive oil, were compared with those obtained by using a modified orthogonal sampling position. In both cases, separations were done using a 10 mM ammonium acetate/ammonium hydroxide buffer solution at pH 10.0 and a constant applied voltage of 25 kV. The operating variables for the mass spectrometry interface were re-optimized for the modified orthogonal orientation. This allowed the sheath liquid, sheath gas flow rates and capillary voltage to be lowered with respect to the co-axial coupling configuration. In addition, the orthogonal sampling position provided a higher selectivity by effect of ion sampling excluding larger droplets-with an increased momentum along the axis-which were drained through the sink at the bottom of the ion source. Also, the new configuration facilitated sample ionization, improved electrospray stability and led to stronger signals as a result. The new system was validated in terms of precision (repeatability), linearity, and limits of detection and quantification. A comparison of the validation data with the results previously obtained by using a commercial co-axial configuration revealed the adapted orthogonal sampling position to provide better repeatability in both migration times and relative peak areas (<1% and 7% respectively with n=15 replicates), a good linear range (with levels in the microgram-per-litre region) and lower limits of detection-especially for the compounds detected with the lowest sensitivity when co-axial ESI was used, as HFA, GEN, FER and VAN finding LOD among 24-3.0 microg L(-1) respectively., (Copyright 2010 Elsevier B.V. All rights reserved.)

A sensitive and expeditious CE-ESI-MS analytical method for the separation, identification and determination of seven selected antioxidants (cinnamic and benzoic acids), including three isomers of coumaric acid (ortho-, meta- and para-) has been developed. In order to obtain the analytical separation, capillary electrophoresis and CE-MS interface parameters (e.g., buffer pH and composition, sheath liquid and gas flow rates, sheath liquid composition, electrospray voltage, etc.) were carefully optimized. The polar fraction containing the selected phenolic acids was obtained using a previously optimized SPE pretreatment. An MS detector in order to extract structural information about the target compounds and facilitate their qualitative analysis was used in the negative ion mode. The proposed off-line SPE CE-ESI-MS method was validated by assessing its precision, LODs and LOQs, linearity range and accuracy. The optimized and validated method was used in order to quantify the selected antioxidants in various samples of virgin olive oil and extra-virgin olive oil obtained from the main olive varieties cropped in Castilla-La Mancha, Spain. Salicylic acid was used as internal standard throughout in order to ensure reproducibility in the quantitative analysis of the oil samples. The results confirmed the presence of hydroxyphenyl acetic, p-coumaric, ferulic and vanillic acids in substantial amounts (microg g(-1) level) in all samples.