Identification of Impurities in Diborane by Gas Chromatography–Mass Spectrometry

Abstract—The impurity composition of diborane synthesized by the hydrogenation reaction of boron chloride was studied for the first time with the chromatography–mass spectrometry method. A GS-GasPro 60 m × 0.32 mm capillary column with silica gel as a sorbent, a GS-CarbonPLOT 25 m × 0.32 mm × 0.25 μm column with a carbon sorbent, and a DB-5MS 30 m × 0.32 mm × 0.25 μm column with methylsiloxane were used to separate impurities. The impurities were identified by comparing their mass spectra with those from published data. The impurities of B₄–B₁₀ higher boranes, cyclohexane, and toluene were identified in diborane. B₆–B₁₀ boranes, cyclohexane, and toluene were found for the first time. The mass spectrum of B₉H₁₅, which was not found in the literature, was obtained and described.