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Iron-hydroxamic acid method

An iron-hydroxamic acid method was used by Andronov and Yudina, who measured air concentrations of vinyl acetate in the presence of butyraldehyde, acetaldehyde, and hydrogen chloride (9.). [Pg.170]

Novakovic presented a colorimetric method for the determination of procaine hydrochloride, either in its bulk form or in various pharmaceutical formulations [41]. The method utilizes conversion of the drug to a hydroxamic acid, and subsequent complexation with iron. The reaction product is violet in color. [Pg.431]

Using two cooled bubblers connected in series and charged with ethanol, 0.5-1 L of air was sampled at a flow of 0.3 L/min. The vinyl acetate was converted to N-hydroxyacetamide by the addition of hydroxylamine hydrochloride and sodium hydroxide. After 30 minutes, the hydroxamic acid was complexed with iron by the addition of hydrochloric acid and ferric chloride. The intensity of the color which developed in 10 minutes was compared to the intensities of standards. The lower limit of detection for this method was reported to be 0.3 yg/mL. [Pg.170]

Other methods, among which thermolysis or photolysis of tetrazene [59], photolysis of nitrosoamines in acidic solution [60], photolysis of nitrosoamides in neutral medium [61], anodic oxidation of lithium amides [62], tributylstannane-mediated homolysis of O-benzoyl hydroxamic derivatives [63, 64], and spontaneous homolysis of a transient hydroxamic acid sulfinate ester [65] could have specific advantages. The redox reaction of hydroxylamine with titanium trichloride in aqueous acidic solution results in the formation of the simplest protonated aminyl radical [66] similarly, oxaziridines react with various metals, notably iron and copper, to generate a nitrogen-centered radical/oxygen-centered anion pair [67, 68]. The development of thiocarbazone derivatives by Zard [5, 69] has provided complementary useful method able to sustain, under favorable conditions, a chain reaction where stannyl radicals act simply as initiators and allow transfer of a sulfur-containing... [Pg.918]

The determination of cephalexin, cefixime, ceftriaxone, cefotaxime based on the Bent-French method, in which degradation products of P-lactam analogs with metal ions form the colored complexes, was developed. Hydroxamic acids formed by hydroxiaminolysis of cephem analogs (1 3), formed complexes with iron (II) ions (Fig. 13) [44]. [Pg.121]

Titrimetric and colorimetric methods are two classical methods for determining the ester contents of alcoholic beverages. The titrimetric procedure involves the treatment of esters with an excess of base followed by determination of the quantity of base required to hydrolyze the esters present in the sample. The colorimetric procedure involves the esters reacting with hydroxylamine in an alkaline solution to form a hydroxamic acid, which forms a colored complex with iron(III). [Pg.1537]

If a measurement of total fatty acid concentration is desired, short of attempting to sum the amounts of each compound found by gas chromatography, some indirect method must be employed. Harwood and Huyser [94] made iron (III) hydroxamates of the fatty acids and measured these colorimetrically. [Pg.391]

Froth flotation has proven to be an efficient method of removing titaniferous impurities (mainly iron-rich anatase) from kaolin clays. Fatty acid reagent, primarily tall oil, is used extensively in the reverse flotation of these impurities. This flotation collector typically requires divalent cations (usually Ca +) to activate the coloured impurities and enhance collector adsorption. This is not very selective since the tall oil can also absorb on the kaolinite particles. Alkyl hydroxamate collectors are relatively new in the kaolin industry but provide significant advantages. Hydroxamates do not require activators, substantially increase the removal of colored impurities and are very selective. [Pg.102]

The obvious method of choice is to model novel structures on natural hydroxamate and catechol siderophores which possess extremely high affinities for iron(III) [35], Hydroxamates possess many advantages for iron(III) chelation, as was outlined in the section on bidentate ligands. However, they tend to possess a low oral activity. Nevertheless, a number have been investigated, including rhodotorulic acid [36], synthetic hexadentate [37] and polymeric hydroxamates [38]. None has proved superior to DFO (Structure 2, Scheme IB). [Pg.199]


See other pages where Iron-hydroxamic acid method is mentioned: [Pg.788]    [Pg.67]    [Pg.2333]    [Pg.149]    [Pg.2332]    [Pg.634]   


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