Esterification via Pyrolytic Methylation

Strongly basic quaternary salts of ammonia, e.g. tetramethyl or trimethylphenylammonium hydroxide in methanol, when co-injected with fatty acids into the heated inlet of a GC, convert the acids into quaternary salts that are immediately pyrolysed into methyl esters and swept onto the analytical column. However, this rapid procedure is not recommended for polyunsaturated fatty acids because isomerization of the double bonds may occur owing to the high inlet temperature and alkalinity of the reagents. It has been reported that tetraalkylammonium fluorides, cyanides or acetates frequently offer considerable advantages over the hydroxides in terms of derivatization selectivity without compromising derivatization efficiency. Regarding on-column benzylation reagents, the 3,5-bis(trifluoromethyl)benzyldimethylphenyl-ammonium fluoride and some related compounds have been shown to be very useful new derivatization reagents with a variety of uses (see the review by Wells in the Further Reading section). Dimethylfor-mamide dimethylacetal (CH3)2NCH(OCH3)2 and its higher alkyl analogues have also been employed as hot inlet esterification agents. Hopes of being able to use them for one-step derivatization of amino acids have not been fulfilled, however.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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