Lipid particulate analysis

Lipid particulate analysis can be achieved with most commercial laser particle counters. Compendial requirements for suspensions also allow for sizing via electron microscopy determinations, which can provide... 

Figure 9.4. Shipboard analysis of particulate lipid classes on the same Chromarod. a Nonpolar neutral lipids and internal standard, partial scan, b Remaining neutral lipids and polar lipids, full scan, increased attenuation at X. Source [404]...

A thin film of oil-like material was visible after 28 d on the exterior surfaces of the SPMD membrane. Analysis of this film indicated that the triolein impurities, oleic acid and methyl oleate, were the major constituents. This external lipid film (Petty et al., 1993) appeared to contain imbibed particulates. Although the film was removed from the SPMDs by solvent rinsing and analyzed separately, some lipid-mediated desorption of particle-associated PCBs and subsequent diffusion into the SPMD may have occurred prior to solvent-removal of the film. This observation suggests the potential for SPMD concentrations to reflect both vapor phase concentrations and to a lesser extent, lipid-extracted particulate-associated residues (see Section 3.9.2.). Unfortunately, concentrations of more chlorinated congeners in particulates collected on GFFs from the NIOSH method were often below quantitation limits, because only a small volume of air was sampled (1 m ) using this active method. 

Figure 9.50a Compound-specific isotope analysis (CSIA) of suspended particulate organic matter (SPOM), lipids, and plant pigments in several estuaries on the Texas coast (USA). The range of 513C in these estuaries was —18 %o to —22 %o. (Modified from Qian et al., 1996.)...

It is more difficult to think of particulate organic material even as a mixture of simple organic compounds. Such simple compounds as are present are most likely adsorbed or absorbed, and will therefore be amenable to solvent extraction (e.g., lipids). The rest undoubtedly consists of polymeric material such as ceU wall detritus and polymerised simpler structures, which sort of material is more suited to chemical class analysis (polysaccharide, protein, etc.) usually after hydrolytic or enzymatic degradation into simpler forms. 

Fig. 10. Principal components analysis (PCA) of Trinity Bay lipid data. Fatty acid and lipid class concentrations in plankton tows from 3 stations were analysed. PL phospholipid, POM particulate organic matter, PUPA 1 polyunsaturated fatty acids, TG triacylglycerol, TL total lipid, 16 1 16 loo7, 16 1/16 16 1/16 0, 16/18 TCkj/ZCis, 16 4 16 4oo1, 18 2 18 2oo6, 18 3 18 3oo3,22 l 22 looll...

Fig. 12. Principal components analysis of sediment data from Trinity Bay. All data used were concentrations per dry weight. Aik 2 alkanes, AMPL acetone-mobUe polar lipids, i + ai iso + anteiso, Iso 2 isoprenoid hydrocarbons, PAH 2 polycyclic aromatic hydrocarbons, PL phospholipid,POM particulate organic matter, TG triacylglycerol, 16 1/16 16 1/16 0,16/18 2Cij/2Ci8, 18 2 18 2oo6, 18 3 18 3oo3, 20 4 20 4oo6, 20 5 20 5oo3...

Methods used for isolation of the 15 000 x g particulate fraction from homogenates of the developing seeds, incubation of these fractions with [1- C] oleoyl-CoA or [2- C]malonyl-CoA in the presence of Mg , CoASH, NADH and/or NADPH, isolation of the very long chain monounsaturated fatty acids, and the analysis of their methyl esters by radio gas chromatography were essentially as described before [4,7]. In several experiments, the total lipids were extracted from the... 

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