On some peculiarities of the low temperature fast atom bombardment mass spectra of ethanol

Low temperature secondary emission mass spectrometry. Cryobiological applications

“…51 This was observed for water solutions of the primary alcohols methanol 57,58 (T e = -138ºC, C e = 77%) 73 and ethanol 50,57,58 (T e = -125ºC, C e = 92.5%), 73,84 which showed a threshold for transformation of the spectral pattern from the featureless to cluster-type at temperatures close to C e (reproducible with temperature cycling around this value). As the liquid eutectic must contain a certain amount of water, abundant sets of water-alcohol clusters were recorded in parallel with pure alcohol clusters.…”

“…The liquid state is formed under LT mass spectrometric conditions due to melting of the sample during thawing or due to formation of a supercooled liquid during cooling (a characteristic, for example, of glycerol). The mechanisms of ion formation in such a case do not differ much from those in ambient liquid matrix FAB; the spectra are of good quality and contain clusters 24,25,[49][50][51]57,58 and there is a strong dependence of the spectral pattern on the viscosity of the liquid, whose increase with decrease of temperature hinders ion production. 26 3.…”

“…In particular, the melting of the eutectic phase can be observed only for systems whose eutectic temperature lies below the mentioned value. 50,51,57 The lifetime of the liquid phase formed due to melting, when possible, is also restricted at reduced pressures. 58 Meanwhile, even within these limitations, useful information on phase transitions (melting, boiling, sublimation, devitrification and crystallization, dehydration of crystalline hydrates) can be obtained by means of LT-FAB during the variation of the temperature of the sample.…”

“…84,85 For the interpretation of LT-FAB mass spectra it is necessary to keep in mind the peculiarities of ion production which result from the types of intermolecular forces acting within the sample and its aggregate state. [45][46][47][48][49][50][51][52][53][54][55] 1. The solid state formed due to freezing of different systems has a number of structural variations.…”

“…[34][35][36][37][38][39][40][41][42][43] The impressive successes of mass spectrometry in "ambient" molecular biology, as well as the potential of LT techniques, inspired the Mass Spectrometric Laboratory of the Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine to initiate, in 1992, work on the application of mass spectrometry to problems of cryobiology and cryobiophysics. [44][45][46][47][48][49][50][51][52][53][54][55] In the course of the initial studies the unique possibilities of LT secondary emission mass spectrometry were revealed, which appeared not to be limited solely to analytical chemical applications. It was found that information concerning some physical processes in the sample, such as phase transitions over a nearly 200ºC interval, can be derived from certain parameters of the LT-FAB mass spectra.…”