A digest of capillary electrophoretic methods applied to lipid analyzes

Abstract

Lipids are naturally occurring organic compounds that can be classified into a number of types based on their solubility in nonpolar organic solvents, and are generally insoluble in water. The great structural variety of these various types of lipids has led them to be components of many different biological substances such as oils, waxes, cellular membranes, tissues and biological fluids. The use of capillary electrophoresis (CE) for the study of lipids during the past 30 years has been relatively rare when compared to its use for other classes of biomolecules, primarily due to their insolubility in water. However, a number of interesting studies have been conducted, and as part of this review, we will present the different approaches that were used, which mainly consist of micellar kinetic chromatography and non-aqueous CE. The main advantages of the use of these techniques compared to GC is the very simple sample preparation that is required and, compared to LC, the very robust and quick separations that can be obtained. In this review, we present the various methods that have been reported in the literature that have been used for the study of fatty acids, phospholipids, glycerides, eicosanoids and sterols, with the inclusion of various tables presenting descriptions of the CE methods used as well as the methods of detection, including UV absorbance, fluorescence, mass spectrometry, and conductivity. This review aims to demonstrate that CE can be easily used for the analysis of lipids.

Capillary electromigration methods for fatty acids determination in vegetable and marine oils: A review

“…CE is a versatile technique that has been intensely employed for FA determination in food samples in the last decades [19,20] and may overcome some limitations of GC, such as the requirement for specific columns, the long run times, and sample derivatization, in some cases. Several CE modes are possible using the same instrument [21], and different detection systems can also be used [22]. CE usually offers the possibility of a faster and simpler analysis when compared to GC.…”

Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications—Updated and completely revised edition

“…Thus, perhaps a good starting point for this section are reviews from Underberg and Waterval (procedures to introduce charges in saccharides [513]) and Wuethrich and Quirino (derivatization for separation and detection in CE [514]). Other reviews have also described derivatization procedures applied to CE analyses [353,515], including those targeting biogenic amines [516], amino acids [517,518], cocaine [519], lipids [520],…”

“…Thus, perhaps a good starting point for this section are reviews from Underberg and Waterval (procedures to introduce charges in saccharides [513]) and Wuethrich and Quirino (derivatization for separation and detection in CE [514]). Other reviews have also described derivatization procedures applied to CE analyses [353, 515], including those targeting biogenic amines [516], amino acids [517, 518], cocaine [519], lipids [520], cells [521], or bacterial samples [522]. Perhaps one of the most important aspects of these procedures is establishing a reproducible procedure to control the yield (or density of the functionalization on large particles), so the extraction process is systematic.…”

Separation of unsaturated C18 fatty acids using perfluorinated‐micellar electrokinetic chromatography: I. Optimization and separation process

“…GC‐based protocols have been optimized very well, especially for the separation of FA methyl esters, and several applications have been described in the literature [ 1 , 2 , 3 ]. Capillary electrophoresis (CE) is another leading technique, now well described for the separation of free FAs [ 4 , 5 ]. In most of the reported separation conditions, the use of sodium dodecyl sulfate (SDS) is necessary, in combination with organic solvents or cyclodextrins.…”