New ultraviolet labelling agents for high-performance liquid chromatographic determination of monocarboxylic acids.
New UV-labelling agents have been synthesized, which are designed to convert monocarboxylic acids into their highly UV-absorbing derivatives for enhancement of the sensitivities of UV detection in high-performance liquid chromatography. The reagents are p-nitrobenzyl, 3,5-dinitrobenzyl and 2-(phthalimino)ethyl p-toluenesulphonates. Each has been prepared by reaction of p-toluenesulphonyl chloride with p-nitrobenzyl alcohol, 3,5-dinitrobenzyl alcohol or N-(hydroxyethyl)phtalimide, respectively, in the presence of sodium hydroxide, and they are stable in the solid state for at least 6 months. Monocarboxylic acids were derivatized to their p-nitrobenzyl, 3,5-dinitrobenzyl or 2-(phthalimino)ethyl esters with each of the above reagents, respectively, then determined by high-performance liquid chromatography with UV detection. In the UV-labelling with each reagent, 18-crown-6 was used as the catalyst. The effects of the reaction solvent, reaction temperature and time and the concentrations of each reagent and the catalyst were also examined.
Funazo
K
K
Department of Chemistry, Osaka Prefectural College of Technology, Japan.
Tanaka
M
M
Yasaka
Y
Y
Takigawa
H
H
Shono
T
T
D002264:Carboxylic Acids / Q000032:analysis*; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014105:Tosyl Compounds
D002264:Carboxylic Acids; D007202:Indicators and Reagents; D014105:Tosyl Compounds