1,721,186 research outputs found
Formation of the European-mass-spectrometry-society, Budapest 25 April 1993
No full textViene presentata la fondazione della Società Europea di Spettrometria di Massa, fondata a Budapest nel 1993
11TH INFORMAL MEETING OF MASS-SPECTROMETRY, BUDAPEST, HUNGARY, 26-28 APRIL 1993
No full textThe article summarizes the outcomes and the main events of the 11th Informal Meeting of Mass Spectrometry, that was held in Budapest
Photolysis of cocaine, morphine, D9-tetrahydrocannabinol and EDDP in water solution.
No full textIn the frame of an ongoing project aimed at understanding the mechanisms of photodegradation and characterizing the phototoxicological profile of drugs and illicit drugs and their photosensitizing role in the biological systems [1-4], the photostability towards UVA and UVB light of cocaine, 9-tetrahydrocannabinol (THC), morphine and EDDP in water solution has been studied. The extent of photolysis and the kind of photoproducts formed have been studied by UV-Vis spectrophotometric analysis, HPLC chromatography, HRMS, and HRMS/MS analysis for accurate mass measurement of small molecules. HPLC analysis allowed us to calculate the yield of photolysis; in particular, Cocaine showed photolysis under high UV light doses, forming demethylated and hydroxylated photoproducts, and the inactive metabolite ecgonyne methyl ester, as already reported in the literature under solar irradiation and photocatalytic processes [5]. Morphine proved also to be unstable under UVB light and, in lower extent, under UVA. It forms various photoproducts, some of them corresponding to oxidation products or deriving from the addition of water to the 7,8 double bond. Also the absorption spectrum of EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine), the main inactive metabolite of methadone, changes under increasing light doses, with the appearance of a new band between 300 and 350 nm. Under both UVA and UVB irradiation, it forms various degradation products, one of them dehydrogenated and another one losing also the ethyl group. For another one we suppose the loss of one of the two aromatic rings. THC also showed photolability under both UVA and UVB light. Its photodegradation products are still under investigation.
Since the photo excited drugs could photo react directly with biological substrates, produce free radicals and reactive oxygen species , or even give rise to toxic photoproducts, particularly oxidation compounds, the phototoxicological profile of illicit drugs and their photoproducts covers particular importance in the study of the toxicity/ phototoxicity of compounds in the aquatic environment
Application of electrospray ionization mass spectrometry to the study of grape anthocyanins
No full textA rapid method for the qualitative and semi-quantitative determination of grape anthocyanins has been developed. It consists of extraction of anthocyanins from grape skins with an ethanol/water/hydrochloric acid solution, purification and concentration by solid phase extraction, and analysis of extracts by direct infusion electrospray mass spectrometry and ion trap multiple mass spectrometry. Two different cultivars of hybrid grapes and a cultivar of Vitis vinifera grape were analyzed and they showed different anthocyanin profiles. Among the compounds detected and characterized in the extracts, four anthocyanin-3-(6-O-p-coumaroyl)5-O-diglucosides were identified in Clinton grape for the first time and their electrospray ionization mass spectra could be obtained for the first time together with those of cyanidin, peonidin, and malvidin 3,5-O-diglucosides. For malvidin 3,5-O-diglucoside and 3-O-monoglucoside a semi-quantitative determination could be achieved that would result interesting for the identification of hybrid grapes and wine
Spettrometria di massa di sostanze organiche naturali in soluzione acquosa mediante membrana siliconica. Parte 1.
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Uv-a Photolysis of Khellin - Products and Reaction-mechanism
No full textPhotolysis at 365 nm of khellin in various solvents was studied: the degradation rate strongly depends on solvent but not on polarity, since it is related to the singlet oxygen lifetime in each solvent. Eight products were isolated and characterized, some of which had previously been described as coming from chemical oxidation of khellin. Both facts support an oxic pathway for photolysis involving singlet oxygen and leading to unstable intermediates. These are rapidly decomposed by nucleophiles, suggesting possible interference-if they are also formed in vivo-with physiological processes during photochemotherapeutic treatment with khellin
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