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Microalgae are unique photosynthetic organisms that are known to accumulate storage lipids in large quantitites and thrive
in saline waters. Before these storage lipids can be used, they must be extracted from the microalgae and converted into usable
fuel. Transesterification of lipids produces fatty acid methyl esters that can be used as a diesel fuel substitute.
Three solvents, 1-butanol, ethanol, and hexane/2-propanol, were evaluated for extraction efficiency of microalgal lipids.
Type of catalyst, concentration of catalyst, time of reaction, temperature of reaction, and quality of lipid were examined
as variables for transesterification. The most efficient solvent of the three for extraction was 1-butanol (90% efficiency),
followed by hexane/2-propanol and ethanol. Optimal yield of fatty acid methyl esters was obtained using 0.6N hydrochloric
acid in methanol for 0.1 h at 70°C. 相似文献
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H.-J. Buschmann E. Schollmeyer L. Mutihac 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(3):199-202
The complexation of protonated amino acid methylesters and amino alcohols bythe ligands 18-crown-6 (18C6) and benzo-18-crown-6 (B18C6) has been studiedin methanol using calorimetric titrations. No influence of the anions upon thestability constants and thermodynamic data for the reaction of protonated aminoacid methylesters with both ligands has been noticed, which indicates the completedissociation of the salts employed. A similar effect has been observed for thecomplexation of protonated and unprotonated amino alcohols with 18C6 andB18C6. The values obtained of the reaction enthalpies for the complexation ofprotonated amino acid methylesters with 18C6 are larger than those correspondingto the complexation with B18C6. The results demonstrate that the complex formationof unprotonated amino alcohols is favored by entropic contributions, while thecomplexation of protonated amino alcohols is favored by enthalpic contributionswith both ligands. The influence of various substituents on the complexation behaviorof amino acid and amino alcohol has also been investigated. 相似文献
3.
Mustafa Tabakci Begum Tabakci Mustafa Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(1-2):51-56
The article describes the synthesis and extraction properties of new (S)-(-)-1-phenylethylamine substituted p-tert-butylcalix[4]arene/calix[4]arene. These compounds have been synthesized via nucleophilic substitution reactions involving 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetra(2-hydroxyethoxy)calix[4]arene (4a), or 5,11,17,23-tetra-H-25,26,27,28-tetra(2-hydroxyethoxy)calix[4]arene (4b) with (S)-(-)-1-phenylethylamine in dry THF. The extraction properties of ligands 5a and 5b towards the some selected α-amino acid methylesters and chiral α-amines are also reported. It has been observed that receptor
5a was an excellent ionophore for α-amino acid methylesters/α-amines and good extractant than 5b. However, both of the ligands did not display any selectivity towards the configurations of this species.
in final form: 17 January 2005 相似文献
4.
Lucia Mutihac Radu Mutihac 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):177-181
The extractability together with the transport through liquid membrane of some amino acid methylesters by using p-tert-butylcalix[4]arene as extractant or carrier was studied. In this context, p-tert-butylcalix[n]arenes (n = 6, 8) were found to act as useful carriers or extractant reagents for l-tryptophan methylester and l-tyrosine methylester. The calix[n]arene derivatives used in experiments extracted amino acids methylesters from the aqueous phase into chloroformic phase in
the presence of tropaeolin 00 ([4(4′-anilinophenylazo)benzenesulphonic acid]) as counterion at
. The extraction and the transport depend on the structure of calixarenes, the structure of amino acids, the pH, and the nature
of anion used as ion pair for cation-receptor complexes. The properties of solvent involved in liquid membrane play an important
role in membrane stability and also in selecting membrane systems. The results demonstrated that the inclusion properties
of the investigated hosts are correlated with their structural properties and also they suggest further possibilities for
optimal separation of amino acids derivatives. 相似文献
5.
Summary The aim of this work was to study the utilisation of coordinative europium compounds as stationary phase additives in gas
chromatography.
The following series of aliphatic nucleophilic compounds were used as solutes: n-alcohols, carboxylic acid methyl esters,
ketones, ethers and 1-alkenes.
A correlation was established between the chromatographic retention values and the NMR chemical shift changes induced by interactions
of the organic molecules with the europium chelate.
The agglomerate formation between the europium chelates and nucleophilic compounds involves changes in the NMR spectra and
selective increases in the GC retention values when adding europium chelates to the stationary phases.
Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984 相似文献
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