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Microalgae have recently become a popular functional food due to their health benefits. Sulfolipids, a class of substances abundant in this matrix, have been reported to have interesting bioactivities, such as anti-carcinogenic activity. However, despite the potential interest in sulfolipids, a dedicated analytical method for their characterization is currently lacking but would significantly increase the coverage of sulfolipids with respect to the direct lipidomic analysis.

To achieve this goal, in this work a procedure, based on graphitized carbon black solid phase extraction, was developed for clean-up and enrichment of sulfolipids (sulfoquinovosyldiacylglycerols and sulfoquinovosylmonoacylglycerols) and it was applied to spirulina (Arthrospira platensis) microalgae. A careful study of the solid phase extraction conditions was performed, first to maximize the recovery of reference standards, then to increase the total number of identified sulfolipids from the spirulina lipid extract. All samples were analysed by ultra-high performance liquid chromatography coupled to high resolution mass spectrometry and lipids were tentatively identified by Lipostar, for a reliable lipid structure assignment. The developed method was compared to the direct lipidomic analysis without enrichment, to establish the enrichment efficiency in terms of number of identifications.

From the comparison, the enrichment procedure proved better and allowed the tentative identification of 199 sulfolipids, which is the largest number reported so far for the Arthrospira platensis species. The described method was validated in terms of precision, accuracy, recovery, limit of quantitation and detection for two sulfolipids. Finally, a relative lipid quantitation based on peak area was carried out on the microalgae sample, which indicated nine abundant sulfolipids as representing ca. 60% of sulfolipids in spirulina microalgae. 

The determination of phospholipids in olive oil is challenging due to their low concentration. For this reason, a comparison of two solid phase extraction procedures, namely weak anionic exchange (WAX) and graphitized carbon black (GCB), is presented for the enrichment of phospholipids. Analyses were performed by liquid chromatography-high resolution mass spectrometry (LC25 HRMS) and lipids were identified by Lipostar software. Compared to the WAX solid phase extraction, GCB demonstrated the best performance and provided 82 identified phospholipids vs only 32.

The final method was validated for some representative phospholipids, showing good repeatability and recovery (63-101%). High sensitivity was reached, with detection limits in the range 9-36 ng g-1, never reported before for phospholipids in olive oil. A semi-quantitative analysis indicated phosphatidic acids and phosphatidylglycerols as the most abundant species, both in number and concentrations. The GCB-LC-HRMS-Lipostar platform can be successfully applied for a comprehensive polar lipidomic characterization of olive oils.

The chemical composition of Cannabis sativa L. has been extensively investigated for several years; nevertheless, a detailed lipidome characterization is completely lacking in the literature. To achieve this goal, an extraction and enrichment procedure was developed for the characterization of phospholipids and sulfolipids. Firstly, a study on the solid-liquid extraction was performed, to maximize the recovery of the considered lipids; the best procedure consisted of a simple extraction with a mixture of methanol and chloroform (1:1, v/v).

The hemp extracts were analyzed by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry and lipids were tentatively identified by Lipostar. To improve the number of identifications, an enrichment method, based on graphitized carbon black solid phase extraction, was evaluated to fractionate phospholipids and sulfolipids into separate eluates. Recovery and matrix effects of the procedure were determined on a mixture of standard lipids, containing representative compounds for each considered lipid class. The optimized method allowed the tentative identification of 189 lipids, including 51 phospholipids and 80 sulfolipids, in the first and second fractions, respectively. The detection of only 6 sulfolipids in the first fraction and 9 phospholipids in the second fraction proved the efficacy of the fractionation method, which also allowed the number of lipid identifications to be increased compared to the same procedure without enrichment, which scored 100 lipids.

Finally, a semi-quantitative analysis permitted the hemp polar lipidome to be characterized. The results of this study allow knowledge of the hemp chemical composition to be improved with a detailed description of its phospho- and sulfolipid profiles. Graphical abstract.

Purpose:

The purpose of this work is to show the automation workflow that can be achieve by using software tools (MassChemSite\WebChembase) for unsupervised and fast data processing and analysis to identify the degradation products of lansoprazole under multiple stress conditions (acid, base, neutral and oxidative stress).

Methods:

Experimental data for the forced degradation study of lansoprazole was obtained following the ICH guidelines Q1A (R2). Lansoprazole was stressed under acidic (0.01 N HCl; room temperature; 60 min), basic (2N NaOH; 80 ⁰C; 72h), neutral (H2O/ACN 50:50, % v/v; 80 ⁰C; 48h) and oxidative (H2O2; room temperature; 60 min) stress conditions. Samples were analyzed via LC-HRMS using an Agilent Q-TOF 6450 coupled to an UV-Vis detector. Data processing was performed using the Derivatization workflow within the MassChemSite application (Molecular Discovery, Ltd). The processed data was consolidated by collecting all the samples for the same experimental condition and automatic comparison of the degradation products obtained in each sample.