Comparison of Laser Mass Spectra Obtained at Ambient Conditions vs. Sample Freezing
A significant advantage of laser mass spectrometry (LMS) is its capability to obtain spatial distributions of analytes within organic matrices [1–2]. Our interest in this area has focused on developing LMS for studying organic components within organic matrices. Many systems of interest contain volatile materials not readily suited to LMS analysis . We have utilized two approaches to obtain LM spectra of volatile materials. The first approach uses a cold probe to freeze volatile organics, significantly reducing their vapor pressure. The second employs a thin formvar [poly(vinyl formal)] film as a seal between the sample and the instrument vacuum . Formvar films employed in this manner allow laser mass analysis to be performed at atmospheric pressure; furthermore, no change in the physical state of the sample occurs when using these films. The potential advantage of using formvar lies in the ability to obtain LMS of liquids and solutions as in FAB, whereas, LMS analysis using the cold probe is performed with the samples in the solid state.
KeywordsLithium Recombination Vinyl Benzyl LiBr
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