Extraction acetic acid

HPLC analysis of anatoxin-a was first carried out by Astrachan and Archer, " who extracted the toxin from Anabaenaflos-aquae using chloroform followed by hydrochloric acid. The HPLC analysis was carried out on an ODS column using hypochlorate-methanol. Other systems used since include acetic acid extraction and analysis on a reversed-phase C g column using methanol-water mobile phase, and extraction in water after ultrasonication and analysis on reversed-phase... 

By a procedure analogous to that described in the preceding experiment, octalone-2 (12 g, 0.08 mole, Chapter 9, Section III) in ether is added to methylmagnesium iodide in the presence of cuprous bromide (0.2 g). After decomposition with ice-acetic acid, extraction with ether, and washing of the ether extract, the ethereal solution is shaken with an equal volume (50-60 ml) of saturated aqueous sodium bisulfite for 3 hours. The mixture is filtered and the filtrate is reserved. The crystals are washed with ether. The filtrate is separated and the aqueous phase is combined with the filtered solid. The combination is acidified (dilute hydrochloric acid) and heated under reflux for 30 minutes. The product thus liberated is extracted into ether, the ether is washed with bicarbonate, then with saturated aqueous sodium chloride solution, and then dried and evaporated. The residual oil is the desired product, bp 250-254°. 

A mixture of 4.9 grams of 5,6-dihydro-6-oxo-morphanthridine, 37 ml of phosphorus oxychloride and 1.5 ml of dimethylaniline Is heated for 3 hours at reflux. The viscous oil, obtained by evaporation of the reaction mixture in vacuo at 60°C, Is diluted with 20 ml of absolute dioxane and, after adding 30 ml of N-methylpiperazine, heated for 4 hours at reflux. The resulting clear solution Is evaporated in vacuo at 60°C to dryness. The residue is distributed between ether and ammonia water. The ethereal solution is separated, washed with water and then extracted with 1 N acetic acid. The acetic acid extract is mixed with ammonia water and then extracted with ether. The ethereal solution is washed with water, dried over sodium sulfate, filtered through alumina and evaporated. 

Following the same procedures described in the above-mentioned study, additional extractive data were obtained for the epoxy phenolic enamel that was irradiated at 4.7-7.1 Mrad at 25 and — 30 °C in the presence of distilled water, 3% acetic acid, and n-heptane. The changes in the amount of extractives resulting from the irradiation treatment are shown in Table IX. In the case of the water and acetic acid extractives, there was no change in either the chloroform-soluble fractions or the chloroform-insoluble fractions. In the case of the n-heptane extractives, the amount of extractives decreased when the irradiation temperature was reduced from +25 to — 30°C. Infrared spectra of the chloroform-soluble residues from the water and acetic acid extractives of the unirradiated and irradiated enamel were identical to the chloroform-soluble residues from the solvent blanks. In other words, the epoxy phenolic... 

Manganese oxides have been used to remediate contaminated soils as well. Hydrous manganese oxides decreased Cd and Pb in rye grass (Lolium spp.) and tobacco (Nicotiana tabacum L.) from soils with pH 7.4-7.8 (Mench et al., 1994). Cadmium concentrations decreased in water and in 0.1 M Ca(N03)2 and acetic acid extracts of treated soils (Mench et al., 1994). 

Anhydro tetracycline oxygenase, 24 601 Anhydrotetracyclines, 24 594 Anhydrous acetic acid, extraction of, 10 786... 

Acetic acid - 8-hydroxyquinoline reagent - dissolve 10 g 8-hydroxy-quinoline in a solution of 2.5 % (v/v) acetic acid and make up to 1 I. (The 8-hydroxyquinoline blocks the readsorption or precipitation of phosphate by active iron and aluminium during acetic acid extraction. Synonyms hydroxybenzopyridine oxine phenopyridine 8-quinolinol. Not carcinogenic, but may be harmful if swallowed, and causes irritation to eyes, respiratory tract and skin safety data sheet at http //www. jtbaker.com/msds/q7250. htm.)... 

Procedure (determination of inorganic phosphate (a) in the acetic acid extract). The 8-hydroxyquinoline forms a precipitate in acidic ammonium molybdate solution, which will interfere unless the aliquot is <5 ml. It should therefore be removed by ignition as follows. Transfer 10 ml acetic acid extract to a 45-ml silica basin, add 0.5 ml 1 M magnesium acetate and evaporate to dryness on a water-bath. (Note do not use magnesium nitrate, which reacts adversely on heating with 8-hydroxyquinoline.)... 

Figure II. Gel filtration of acetic acid extracts of flour and of dough mixed different times (27)...

Metaphosphoric acid + acetic acid extraction AA oxidized to DHAA using Norit total vitamin C as DHAA derivatized with o-phenylenediamine... 

Sodium 1-heptanesulfonate and acetic acid extraction, filtration. Elution through a Cl 8 SepPak cartridge, conditioned with MeOH, sodium 1-heptanesulfonate. Elution with watcr-ACN mixture to remove interferents and glycoalkaloids elution with ACN and diammonium phosphate buffer. 

The performance of Bi-GECE was also tested for measuring lead and cadmium in tap water and acetic acid extracted soil sample and the results are shown in Procedure 7. 

Due to the possible toxic effects of Hg, alternative electrodes have been sought, such as bismuth, which has recently been used by Kadara and Tothill [155,156] for the determination of Pb2+ and Cd2+ at an SPCE. In this investigation, stripping chronopotentiometric measurements were carried out by depositing a metallic film of bismuth in situ with the target metal ions (lead and cadmium). A deposition potential was applied to preconcentrate the analytes, after which, a constant current was applied to strip the preconcentrated analytes until a limit of —0.2 V. The concentrations for Pb2+ and Cd2+ in the wastewater samples and acetic acid extracts of soils were quantified by the use of a multiple standard addition method. 

Standard official methods have been described for the determination of nitric-perchloric acid-soluble nickel [174] and acetic acid-extractable nickel [175] in soil. To determine nitric acid-perchloric acid-soluble nickel [174], the acid digest is dissolved in hydrochloric acid and the nickel is determined by atomic absorption spectrometry. To determine extractable nickel, the nickel is first extracted from the soil with 0.5 M acetic acid and the nickel is then converted to the ammonium pyrrolidine dithiocarbamate complex. Extraction of the complex with chloroform provides an extract for the determination of nickel by atomic absorption spectrometry. 

A standard official method has been published for the spectrometric determination of nitric-perchloric acid-soluble zinc [244] and 0.5 M acetic acid-extractable zinc [245] in soils. 

For the sample digestion of sediments, Scancar et al. found that significantly lower results were obtained for chromium, nickel and cadmium when aqua regia digestion was employed, compared to total acid dissolution and acetic acid extraction methods [266]. 

Propachlor Maize, potatoes Water extraction, steam distillation, acetic acid extraction GC with FID [111]... 

HPLC Assay of an ethyl alcohol-acetic acid extract against a Reference Standard material (chromatographic conditions reversed-phase mode Cjo column methanol—water—acetic acid, 50 49 1 (v/v), mobile phase detection at 254 nm [79]) and (c) extraction of tablets with methanol or ethanol and UV measurements at 260 or 262 nm. Linearity in the 3—15 Ug/ml and standard errors of less than 2% were reported [65,109,110]. A similar procedure is used for the determination of the Content Uniformity of the tablets [79].. ... 

Quevauviller, Ph., Rauret, G., Rubio, R., Lopez-Sanchez, J.-F., Ure, A., Bacon, J. and Muntau, H. (1997c) Certified reference materials for the quality control ofEDTA- and acetic acid-extractable contents of trace elements in sewage sludge amended soils (CRMs 483 and 484). Fresenius J. Anal. Chem., 357, 611. 

After about the first 6-8 hours an additional 30 ml of 70% ethyl alcohol may be added. Remove about 50% of the solvent by distillation in vacuo. Add a small amount of ice water and acidify with glacial acetic acid. Extract with chloroform (6-8 times), since the product precipitates from the acetic acid solution as a thick emulsion which cannot be filtered. Concentrate the chloroform extracts to a small volume and precipitate the product with hexane to give crude 8-chloro-6,ll-dihydro-ll-(4-piperidylidene)-5H-benzo[5,6]cyclohepta[l,2-b]pyridine acetic acid salt, m.p. 197-200°C. Recrystallize from benzene-hexane to obtain the product, m.p. 199-200°C. Yield 4.0-4.5 g. 

The polypeptide product was simultaneously removed from the resin and completely deprotected by treatment with anhydrous liquid HF. A mixture of 2.0 g of protected polypeptide resin and 2 mL of anisole (scavenger) in a Kel-F reaction vessel was treated with 20 mL of redistilled (from CoF3) anhydrous liquid HF at 0°C for 30 minutes. The HF was evaporated under vacuum and the residue of (pyro)-Glu-His-Trp-Ser-Tyr-3-(2-naphthyl)-D-alanyl-Leu-Arg-Pro-Gly-NH2,as its HF salt, was washed with ether. The residue was then extracted with glacial acetic acid. The acetic acid extract was lyophilized to yield 0.8 g of crude material. The crude polypeptide was loaded on a 4x40 cm. Amberlite XAD-4 column (polystyrene-4% divinylbenzene copolymer) and eluted with a concave gradient from water (0.5 L) to ethanol (1 L). The tubes containing fractions from effluent volume 690 mL to 1,470 mL were pooled and stripped to dryness to yield 490 mg of partially purified polypeptide. 

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