Quantitation of myo‐inositol as its hexakis(trifluoroacetyl) derivative with negative ion chemical ionization mass spectrometry

Highly volatile hexakis(trifluoroacetyl) derivatives of myo‐inositol and hexadeutero‐myo‐inositol have been prepared and analysed by capillary column gas chromatography/mass spectrometry. The electron impact and negative ion (methane) chemical ionization mass spectra of these compounds have been determined. Negative ion chemical ionization mass spectrometric analysis of hexakis(trifluoroacetyl)‐myo‐inositol achieves a sensitivity one order of magnitude greater than electron impact mass spectrometric analysis of hexakis(trimethylsilyl)‐myo‐inositol at appropriate selected ions. Stable isotope dilution measurement of myo‐inositol versus hexadeutero‐myo‐inositol employing gas chromatography/negative ion chemical ionization mass spectrometry of the hexakis(trifluoroacetyl) derivatives is demonstrated, and this method is applied to the detection of inositol derived from hydrolysis of water‐soluble inositol phosphates obtained from isolated pancreatic islets.