Search results for "Fatty alcohol"
showing 3 items of 23 documents
On the determination of underivatised fatty alcohol ethoxylates by electrospray ionisation–mass spectrometry
2006
Abstract The oligomers of fatty alcohol ethoxylates (FAEs) exhibit large sensitivity differences in mass spectrometry with electrospray ionisation (ESI–MS) and atmospheric pressure chemical ionization (APCI). Standards of the oligomers from m = 1 to 7 ethylene oxide units (EOs) and linear alkyl chains from n = 10 to 18 carbon atoms were infused to examine the relative sensitivities or response factors in several media. The response factors of the [M + H]+ and [M + Na]+ peaks in 9:1 acetonitrile/water and methanol/water media containing acid buffers increased following irregular patterns when n and m increased. In methanol/water the response factors depended on the parity of m, being larger …
Micellar fluorescence enhancement of carbamate pesticides
1990
Abstract Different studies have been carried out on the interaction of carbamate pesticides, such as carbofuran and carbaryl, with nonionic and anionic surfactants. Micellar fluorescence enhancements (MEF) of 15–20 for carbofuran in the presence of fatty alcohol ethylene oxide condensates, and of 3.7–8.6 in the presence of anionic surfactants at neutral pH have been obtained. Carbaryl does not interact with surfactants, but when it is hydrolysed to 1-naphthol, MEF values of the order of 2 are obtained in the presence of nonylphenol ethylene oxide condensates. The experimental parameters have been optimized in order to obtain maximum fluorescence. The mechanisms involved in the fluorescence …
Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿
2010
ABSTRACT Enzymes involved in oxidation of long-chain n -alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n -alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n -alkanes from dodecane (C 12 ) to hexatriacontane (C 36 ) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4…