Search

A method of surface ionization mass spectrometry is developed for the direct detection and analysis of morphine in biofluid. Morphine mixed with human blood is studied for the first time using this method without its preliminary chromatographic separation and extraction. The mechanism of the ionization of a mixture of morphine in biofluids is consistent with the previously established regularities of the surface ionization of nitrogen-containing compounds. The limit of detection for morphine mixed with blood by the method was tens of picograms with a linear range of more than two orders of magnitude. It was shown that because of the high selectivity of the method, such a complex sample can be analyzed without its preliminary chromatographic separation and extraction, which will significantly reduce the time of analysis of the sample, and also, because of the high sensitivity of the method, reduce false negative results., Author(s): Sh. D. Akhunov [sup.1], B. Sh. Kasimov [sup.1], Kh. B. Ashurov [sup.1], D. T. Usmanov [sup.1] Author Affiliations: (1) grid.419209.7, 0000 0001 2110 259X, Arifov Institute of Ion-Plasma and [...]

Under the same experimental conditions, the processes of adsorption and the heterogenous reaction of dissociation on the surface and thermal desorption of C17H19NO3 morphine molecules with m/z 285 amu on the surface of oxidized tungsten are studied by the nonstationary surface ionization, such as the voltage modulation and flux modulation methods. The experiments are carried out using a high-vacuum mass spectrometer, in which a "black chamber" is used, all walls of which are cooled with liquid nitrogen. The kinetic characteristics of the processes of thermal desorption and the heterogeneous reaction of the dissociation of molecules on the surface, such as the rate constant of thermal desorption in the ionic and neutral states K+ and K0, the corresponding activation energies of thermal desorption E+ and E0, the pre-exponential factors C and D, as well as the rate constant of the heterogeneous dissociation reaction K d and the activation energy of heterogeneous reaction of dissociation on the surface, exponential factors in the equation of continuity of the surface concentration for C9H7N+CH3 radicals with m/z 144 amu during the adsorption of morphine molecules on the surface of oxidized tungsten are determined. [ABSTRACT FROM AUTHOR]