TRITON-X-100 AS A REFERENCE COMPOUND FOR AMMONIA HIGH-RESOLUTION CHEMICAL-IONIZATION MASS-SPECTROMETRY AND AS A TUNING AND CALIBRATION COMPOUND FOR THERMOSPRAY

The non-ionic surfactant Triton X-100, 1-(1,1,3,3,-tetramethylbutyl)-4-[poly(1,2-ethanediol)]benzene, has been evaluated as a reference material for positive-ion high-resolution ammonia chemical ionization (CI) mass spectrometry and as a tuning and calibration material for positive-ion thermospray mass spectrometry (TSP). When ammonia is used as the CI reagent gas, Triton-X-100 produces evenly spaced ions that are 44 u apart. Triton X-100 can be volatilized from a solids probe and is routinely used as the reference material for high-resolution measurements. A reference table has been constructed from the theoretical values for the different masses. Triton X-100-Reduced and Triton X-405-Reduced were also evaluated as additional reference compounds. As a calibration and tuning compound for TSP, Triton X-100 affords an envelope of ions centred around m/z 600-700 with ions observed above m/z 1000. Triton X-100-Reduced affords a similar envelope although the ions observed are 6 u higher in mass.