Lipids high-performance liquid

Of the various types of separation processes, thin layer and column chromatography are most useful for intact lipids. High performance liquid chromatography (HPLC) is also rapidly becoming more popular, especially for the fractionation of molecular species of a given lipid class. 

High performance liquid chromatography (HPLC) has been by far the most important method for separating chlorophylls. Open column chromatography and thin layer chromatography are still used for clean-up procedures to isolate and separate carotenoids and other lipids from chlorophylls and for preparative applications, but both are losing importance for analytical purposes due to their low resolution and have been replaced by more effective techniques like solid phase, supercritical fluid extraction and counter current chromatography. The whole analysis should be as brief as possible, since each additional step is a potential source of epimers and allomers. 

Passi, S., Rothschildboros, M.C., Fasella, P., Nazzaroporro, M. and Whitehouse, D. (1981) An application of high performance liquid chromatography to analysis of lipids in archaeological samples. Journal of Lipid Research 22, 778 784. 

The purity of all lipids and anthracyclines exceeded 98% based on thin-layer chromatography (TLC) and/or high-performance liquid chromatography (HPLC) analysis, performed as described by Barenholz and coworkers (38,49,50). 

The mean sizes obtained were 500 150, 350 77, 192 25, and 100 16, for 0.6, 0.4, 0.2, and 0.1pm liposomes, respectively. Drug concentration was determined by spectrophotometric assay of chromophoric complex between the BP and copper (II) ions (63) or by high performance liquid chromatography (HPLC) (64). Lipid concentration was determined by Bartlett method (65). Stability of the liposomes was determined by examining drug leakage. Then 400 pL of liposomal formulations were centrifuged... 

Stith BJ, Hall J, Ayres P, Waggoner L, Moore JD, Shaw WA. Quantification of major classes of Xenopus phospholipids by high performance liquid chromatography with evaporative light scattering detection. Journal of Lipid Research A, 1448-1454, 2000. 

Fig. 4.5.2 Actual strategies for CDG diagnosis. Initial investigations on CDG patients are routinely carried out by isoelectric focusing (IEF) of serum transferrin. With a CDG type I pattern, subsequent analysis should imply determination of phosphomannomutase (PMM) and phos-phomannose isomerase (PMI) activities. Further studies, like analysis of the lipid-linked- and protein-bound-oligosaccharides, determination of enzyme or sugar transporter activities and molecular biology studies often have to be performed in more specialised laboratories. HPLC High-performance liquid chromatography, TLC thin-layer chromatography...

Certain classes of lipids are susceptible to degradation under specific conditions. For example, all ester-linked fatty acids in triacylglycerols, phospholipids, and sterol esters are released by mild acid or alkaline treatment, and somewhat harsher hydrolysis conditions release amide-bound fatty acids from sphingolipids. Enzymes that specifically hydrolyze certain lipids are also useful in the determination of lipid structure. Phospholipases A, C, and D (Fig. 10-15) each split particular bonds in phospholipids and yield products with characteristic solubilities and chromatographic behaviors. Phospholipase C, for example, releases a water-soluble phosphoryl alcohol (such as phosphocholine from phosphatidylcholine) and a chloroform-soluble diacylglycerol, each of which can be characterized separately to determine the structure of the intact phospholipid. The combination of specific hydrolysis with characterization of the products by thin-layer, gas-liquid, or high-performance liquid chromatography often allows determination of a lipid structure. 

In the determination of lipid composition, the lipids are first extracted from tissues with organic solvents and separated by thin-layer, gas-liquid, or high-performance liquid chromatography. 

However, during the past three decades, an analytical method has been developed that currently rivals and may soon surpass the traditional liquid chromatographic techniques in importance for analytical separations. This technique, high-performance liquid chromatography (HPLC), is ideally suited for the separation and identification of amino acids, carbohydrates, lipids, nucleic acids, proteins, pigments, steroids, pharmaceuticals, and many other biologically active molecules. 

Redden, RR. and Huang, Y.-S. 1991. Automated separation and quantitation of lipid fractions by high-performance liquid chromatography and mass detection. J. Chromatogr. 567 21-27. 

Caboni, M.F. and Rodriguez-Estrada, M.T. 1997. High-performance liquid chromatography coupled to evaporative light scattering detection in lipid analysis Some application. Seminars in Food Analysis 2 159-169. 

Fig. 30 Silver ion high-performance liquid chromatography (Ag-HPLC-FID) with flame ionization detector (FID) analysis of the triacylglycerols of chromatographed Crepis alpina seed oil. Ag-HPLC-FID conditions 0.5-mg sample 5-micron Chromspher Lipids column (Chrompack International, Middelburg, The Netherlands) (4.6 X 250 mm) mobile phase 0.5% acetonitrile in hexane (v/v) flow rate 1.0 ml/min FID. Chromatogram peak triacylglycerol fatty acid abbreviations S, saturated (palmitic and stearic) O, oleic L, linoleic and Cr, crepenynoic fatty acids.

However, in a more recent paper, Caboni et al. described that the aforementioned method was not applicable for all types of food products (32). Hence, only 30% and 53% of the PL of a total lipid extract of cheese and dried egg powder, respectively, were recovered. High-performance liquid chromatography analysis revealed that the acidic phospholipids PG and PI were not... 

JA Singleton. Enrichment of phospholipids from neutral lipids in peanut oil by high performance liquid chromatography. J Am Oil Chem Soc 70 637-638, 1993. 

A Arduini, A Peschechera, S Dottori, AF Sciarroni, F Seraflni, M Calvani. High performance liquid chromatography of long-chain acylcamitine and phospholipids in fatty acid turnover studies. J Lipid Res 37 684-689, 1996. 

P Soudant, Y Marty, J Moal, JF Samain. Separation of major polar lipids in Pecten maximums by high performance liquid chromatography and subsequent determination of their fatty acids using gas chromatography. J Chromatogr 673 15-26, 1995. 

RA Moreau, PT Asmann, HA Norman. Analysis of major classes of plant lipids by high performance liquid chromatography with flame ionization detection. Phytochemistry 29 2461-2466, 1990. 

FD Conforti, CH Harris, JT Rinehart. High performance liquid chromatographic analysis of wheat flour lipids using an evaporative light scattering detector. J Chromatogr 645 83-88, 1993. 

RA Moreau, MJ Powell, SF Osman, BD Whitaker, WF Fett, L Roth, DJ O Brien. Analysis of intact hopanoids and other lipids from the bacterium Zymomonas mobilis by high performance liquid chromatography. Anal Biochem 224 293-301, 1995. 

TC Markello, J Guo, WA Gahl. High performance liquid chromatography of lipids for the identification of human metabolic diseases. Anal Biochem 198 368-373, 1991. 

WW Christie. Separation of lipid classes by high-performance liquid chromatography with the mass detector. J Chromatogr 361 396-399, 1986. 

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