Negative-ion electrospray and fast atom bombardment mass spectrometry of esters of boron acids

✍ Scribed by Malcolm E. Rose; Darren Wycherley; Steven W. Preece

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 603 KB
• Volume: 27
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210270806

✦ Synopsis

It is shown that both electrospray and fast atom bombardment mass spectrometry provide excellent negative-ion mass spectra of the anionic esters of boric, boronic and borinic acids. For electrospray, contact of the esters with water causes some hydrolysis but, in most cases, spectra of the intact molecular anions are readily obtained. For fast atom bombardment, solvents that chelate with the boron esters must be avoided. Tetraethylene glycol diethyl ether, pentaethylene glycol dimethyl ether or hexaethylene glycol dimethyl ether are suitable solvents. Negative-ion electrospray mass spectra showed few, if any, fragment ions, whereas fast atom bombardment generally produced abundant M-ions and several fragment ions of low abundance. It is shown that a simple reaction with dibenzeneborinic acid converts diols such as monoglycerides and monoalkyl glyceryl ethers into anionic borinate esters as a pre-ionization procedure for analysis by electrospray or fast atom bombardment mass spectrometry.