Thermospray mass spectrometric analysis of phenazines

Positive and negative thermospray mass spectra have been recorded for a number of phenazines at the submicrogram level. The spectra are dominated by molecular ion species ([M + H] + , [M – H] − ) with minimal fragmentation. The gas chromatographic/electron impact mass spectrometric behaviour of the phenazines was also investigated. A number of phenazines were not amenable to gas chromatographic/mass spectrometric analysis without derivatization; in contrast, thermospray mass spectrometric data were obtained for each phenazine. Thermospray liquid chromatography/mass spectrometry has been applied to identify phenazine‐1‐carboxylic acid and 2‐hydroxyphenazine in culture filtrates of Pseudomonas aureofaciens and 1‐amidophenazine from Pseudomonas aeruginosa .