Search results for "Ethyl sulfate"
showing 7 items of 7 documents
Flow chemistry: Imidazole-based ionic liquid syntheses in micro-scale
2010
The quarternization of an N-atom in the 1-methyl-imidazole with different alkylating agents was investigated to form so-called Ionic Liquids. (3-Chloropropyl)-trimethoxysilane, 1-chlorobutane, diethyl sulfate and methyl trifluoromethanesulfonate were used as alkylating agents. Reaction kinetics range from very slow to instantaneous and the reaction heat from endothermal to extremely exothermal respectively. The reactions were performed under flow conditions using different types of microstructured reactors as well as pre-structurized reactants in the micro-scale. Unusual heat management with integrated heat pipes allow safer performing of highly exothermal reactions with comparably high thr…
Multicompartment Micelles with Adjustable Poly(ethylene glycol) Shell for Efficient in Vivo Photodynamic Therapy
2014
We describe the preparation of well-defined multicompartment micelles from polybutadiene-block-poly(1-methyl-2-vinyl pyridinium methyl sulfate)-block-poly(methacrylic acid) (BVqMAA) triblock terpolymers and their use as advanced drug delivery systems for photodynamic therapy (PDT). A porphyrazine derivative was incorporated into the hydrophobic core during self-assembly and served as a model drug and fluorescent probe at the same time. The initial micellar corona is formed by negatively charged PMAA and could be gradually changed to poly(ethylene glycol) (PEG) in a controlled fashion through interpolyelectrolyte complex formation of PMAA with positively charged poly(ethylene glycol)-block-p…
Die vollständige methylierung phenolischer hydroxylgruppen von struktureinheitlichen mehrkernverbindungen
1965
Die phenolischen Hydroxylgruppen von aus p-Kresol und Formaldehyd hergestellten Mehrkernverbindungen liesen sich nicht mit Methyljodid oder Diazomethan vollstandig methylieren. Wie Loslichkeitsversuche zeigten, sind die untersuchten Mehrkernverbindungen weder als Kryptophenole4,5 noch als behinderte Phenole7 anzusehen; es liegen phenolische Verbindungen mit ausergewohnlichem Reaktionsverhalten vor. Durch Behandeln der Verbindungen in Dioxan mit metallischem Natrium und Dimethylsulfat gelang die Herstellung der Permethylather. Das ist ein weiterer Beweis fur die angegebene Kettenstruktur der Mehrkernverbindungen. Der Versuch, auch halogenhaltige Mehrkernverbindungen an den Hydroxylgruppen au…
�ber das Verhalten und Reaktionsverm�gen von glatter Muskulatur und Herzmuskulatur in chloridfreiem Medium (Methylsulfat-Tyrode-L�sung)
1961
Um die Bedeutung der Chlorid-Ionen fur die Funktion von glatter Muskulatur und Herzgewebe zu untersuchen, wurden die Chlorid-Ionen der Tyrodelosung durch die einwertigen, nicht permeierenden und indifferenten Methylsulfat-Ionen ersetzt. Die Versuche wurden am Meerschweinchen-Ileum, Kaninchen-Duodenum, Ratten-Uterus, spontan schlagenden Vorhof des Meerschweinchens und am Froschherz nach Straub durchgefuhrt. Keines der genannten Organe reagierte beim Uberfuhren in chloridfreies Medium oder bei stundenlangem Aufenthalt in Methylsulfat-Tyrodelosung mit einer wesentlichen Funktionsanderung. Wahrend die Herzmuskulatur in chloridfreiem Milieu unverandert auf positiv oder negativ inotrop wirksame S…
The [3,3′-Co(1,2-C2B9H11)2]– anion as a platform for new materials: synthesis of its functionalized monosubstituted derivatives incorporating synthon…
2003
[3,3′-Co(8-C5H10O-1,2-C2B9H10)(1′,2′-C2B9H11)] (2) was synthesized by reaction of the caesium salt of [Co(C2B9H11)2]− with dimethyl sulfate in the presence of sulfuric acid as catalyst and tetrahydropyrane as solvent; the zwitterionic compound (2) yielded [3,3′-Co(8-C4H4N-(CH2)5-O-1,2-C2B9H10)(1′,2′-C2B9H11)]− (6), [3,3′-Co(8-C8H6N-(CH2)5-O-1,2-C2B9H10)(1′,2′-C2B9H11)]− (7), and [3,3′-Co(8-C12H8N-(CH2)5-O-1,2-C2B9H10)(1′,2′-C2B9H11)]− (8) through the nucleophilic addition of potassium pyrrolyl, indolyl and carbazolyl, respectively. The nucleophilic addition of the same salts on [3,3′-Co(8-C4H8O2-1,2-C2B9H10)(1′,2′-C2B9H11)] (1) yielded, respectively, [3,3′-Co(8-C4H4N-(CH2)2-O-(CH2)2-O-1,2-C…
Estimation of alcohol consumption during >Fallas> festivity in the wastewater of Valencia city (Spain) using ethyl sulfate as a biomarker
2016
Alcohol consumption has been increasing in the last years and it has become a sociological problem due its derived health and safety problems. Ethyl sulfate is a secondary metabolite of the alcohol degradation that is excreted through the urine (0.010-0.016%) after alcohol ingestion and it is quite stable in water. In this study, a new methodology to determine ethyl sulfate by ion-pair liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. Different ion-pairs and additives were tested directly in the sample extracts or in the mobile phase. The best ion-pair was set up adding 0.5M of tributylamine and 0.1% of formic acid to the sample. The limit of quantification was 0.3μgL…
Determination of ethyl sulfate – a marker for recent ethanol consumption – in human urine by CE with indirect UV detection
2006
A CE method for the determination of the ethanol consumption marker ethyl sulfate (EtS) in human urine was developed. Analysis was performed in negative polarity mode with a background electrolyte composed of 15 mM maleic acid, 1 mM phthalic acid, and 0.05 mM cetyltrimethylammonium bromide (CTAB) at pH 2.5 and indirect UV detection at 220 nm (300 nm reference wavelength). This buffer system provided selective separation conditions for EtS and vinylsulfonic acid, employed as internal standard, from urine matrix components. Sample pretreatment of urine was minimized to a 1:5 dilution with water. The optimized CE method was validated in the range of 5-700 mg/L using seven lots of urine. Intra-…