Online Extraction Followed by LC–MS/MS Analysis of Lipids in Natural Samples: A Proof-of-Concept Profiling Lecithin in Seeds

Abstract

Sample preparation is usually a complex and time-consuming procedure, which can directly affect the quality of the analysis. Recent efforts have been made to establish analytical methods involving minimal sample preparation, automatized and performed online with the analytical techniques. Online Extraction coupled with Liquid Chromatography–Mass Spectrometry (OLE–LC–MS) allows a fully connected extraction, separation, and analysis system. In this work, the lecithin profile was investigated in commercial sunflower, almonds, peanuts, and pistachio seeds to demonstrate that the concept of extraction, followed by the online analysis of the extract, could be applied to analyze this class of analytes in such complex solid matrices without a prior off-line solvent extraction step. The extraction phase gradient method was optimized. Two different analytical columns were explored, one being a conventional C18 (50 × 2.1 mm, 1.7 µm SPP) and the other a novel self-packed SIGO-C18ec (100 × 0.5, 5 µm FPP), which resulted in better separation. The analysis repeatability was investigated, and suggestions to improve it were pointed out. A characteristic ion with a m/z of 184, related to lysophosphatidylcholine structure, was used to identify the lecithin compounds. The temperature effect on the chromatograms was also explored. In short, it was found that the OLE–LC–MS approach is suitable for the analysis of lecithin compounds in seeds, being a promising alternative for lipidomics approaches in the near future.

Recent Trends in Graphene-Based Sorbents for LC Analysis of Food and Environmental Water Samples

“…In seed samples, a capillary column packed with a SiGO-C18ec stationary phase, produced by the functionalization of SiGO particles with C18 followed by end-caping (as previously mentioned), was employed to separate lecithin, a common phospholipid component in foods. This study evaluated the viability of applying an online liquid extraction (OLE) system coupled with an LC-MS to evaluate the hyphenated extraction and separation of lecithin from the pounder of seeds [ 82 ]. The SiGO-C18ec column presented a better separation than a conventional C18 column in reversed-phase (RP) separation mode for this application.…”

“…The GQDs were prepared by hydrothermal synthesis using GO as starting material. Also, capillary columns packed with the SiGO-C18ec particles prepared similarly to [ 82 ] have been reported to separate a multiclass mixture presenting a different selectivity from the conventional C18 column among the separated compounds, including pesticides such as carbofuran, hexazinone, and clomazone [ 71 ].…”

Green Chromatographic Methods and in Vitro Pharmacological Analysis of Varronia curassavica Leaf Derivatives

“…Once the sample is inserted in the guard column, the following processes can then take place: solid-liquid extraction, solid phase extraction, filtration (in the guard column), and analysis. [15,16] Considering the importance of V. curassavica as a medicinal plant and the desire to explore its pharmacological properties without causing harm to the environment, it is essentially important to develop a highly efficient analytical method that is based on the principles of Green Chemistry and which can help us effectively determine the chemical composition of V. curassavica and its derivatives, as well as their pharmacological properties. As the OLE-LC system is found to comply with the principles of Green Chemistry, the application of this technique for the pharmacological analysis of V. curassavica and its derivatives will certainly help us achieve our intended purposes.…”

“…The OLE‐LC system employs only the chromatographic equipment components including holders, empty cartridges of guard column, silica, and membrane filter, where the holder is closed and coupled to the injector or the column. Once the sample is inserted in the guard column, the following processes can then take place: solid‐liquid extraction, solid phase extraction, filtration (in the guard column), and analysis [15,16] . Considering the importance of V. curassavica as a medicinal plant and the desire to explore its pharmacological properties without causing harm to the environment, it is essentially important to develop a highly efficient analytical method that is based on the principles of Green Chemistry and which can help us effectively determine the chemical composition of V. curassavica and its derivatives, as well as their pharmacological properties.…”

Applicability and Limitations of a Capillary-LC Column-Switching System Using Hybrid Graphene-Based Stationary Phases

“…Graphene-based materials have also been explored as packing material for analytical columns in LC [ 28 ]. Graphene sheets fixed to silica particles [ 35 , 36 ], graphene oxide sheets fixed to silica particles functionalized with C18 [ 37 , 38 ], graphene sheets fixed to silica particles modified with gold nanoparticles [ 39 ], and cellulose-coated reduced oxide sheets fixed to silica particles [ 40 ] are examples of some materials that have been applied as stationary phases in liquid chromatography. Columns packed with the SiGO-C18ec phase have been successfully used in quantitative analyses of hormones in urine samples [ 41 ].…”