Probing the formation of monoalkyl carbonates and pyrocarbonates in water with electrospray ionization mass spectrometry

Author(s)

Rajh Vidal, Denis Tadeu ^[1] ; Santana, Michele Alves ^[1] ; Hotta, Guilherme Minoru ^[1] ; Godoi, Marla Narciso ^[2] ; Eberlin, Marcos Nogueira ^[2] ; do Lago, Claudimir Lucio ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Sao Paulo - Brazil

^[2] Univ Estadual Campinas UNICAMP, Inst Chem, Thomson Mass Spectrometry Lab, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: RSC ADVANCES; v. 3, n. 41, p. 18886-18893, 2013.
• Web of Science Citations: 5

Abstract

The anionic hemiesters of carbonic acid with aliphatic alcohols were demonstrated to be formed in aqueous medium containing HCO3- or CO32- by using electrospray ionization mass spectrometry (ESI-MS). Some monoalkyl carbonates (MACs) have been previously detected by capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-(CD)-D-4), but ESI-MS is structurally diagnostic and more sensitive allowing unequivocal characterization, which allowed, for the first time, detection of hydrogen pyrocarbonate and monoalkyl pyrocarbonates (MAPs). Methanol, ethanol, and different isomers of alcohols from C3 to C6 were studied. The relatively slow kinetics of formation of the MACs allowed us to confirm their formation in solution before the electrospray process takes place. The loss of CO2 to form the corresponding alkoxide is the most important process in gas phase dissociation, but dehydro-alkoxides were also observed. Monocyclohexyl and monocyclopentyl carbonates were also characterized by ESI-MS. These species, formed from cyclohexanol and cyclopentanol in diluted aqueous solution of HCO3-, are important because these alcohols are prototypes for the hydroxyl-containing portion of sterols. No biological role has been yet attributed to either MACs or MAPs, but their spontaneous formation in aqueous solution at room temperature indicates that these species are present in biological media. (AU)

• FAPESP's process: 12/15467-9 - Study of the properties of the carbonate adducts of 1,3-butanediol and panthenol in aqueous medium
• Grantee: Michele Alves Santana
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 11/02156-2 - The use of capillary electrophoresis with contactless conductivity detection for obtaining analytical and physicochemical parameters of peroxycarbonate, peroxyacids, and monoethyl pyrocarbonate.
• Grantee: Denis Tadeu Rajh Vidal
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 12/06642-1 - Formation and properties of adducts of organic hydroxy-compounds with carbonate in aqueous medium and biological conditions
• Grantee: Claudimir Lucio Do Lago
• Support Opportunities: Regular Research Grants