scholarly journals The determination of nitric and nitrous acids in acetic acid solution. The stability of nitric acid in acetic acid solution

The Analyst ◽  
1912 ◽  
Vol 37 (436) ◽  
pp. 303
Author(s):  
Kennedy J. P. Orton ◽  
William Herbert Gray
1966 ◽  
Vol 49 (2) ◽  
pp. 407-412
Author(s):  
Harry Shuman ◽  
Ugo R Cieri

Abstract A method is presented for determining residues of chlorbenside including its sulfoxide and sulfone oxidation products. The method employs the Mills-Onley-Gaither extraction procedure. Chlorbenside and chlorbenside sulfoxide are converted to chlorbenside sulfone by a short oxidation with chromic-acetic acid solution. Chlorbenside sulfone is isolated from interfering pesticides and most oxidation products on an aluminum oxide column and determined by electron capture gas chromatography. Recoveries for mixtures of the three components added to apple samples at 0.3–5 ppm (calculated as chlorbenside) were between 92 and 110%.


1971 ◽  
Vol 54 (5) ◽  
pp. 1024-1026 ◽  
Author(s):  
David C Holland

Abstract Distillation of ground walnut meats from a slightly acidified concentrated NaCl solution gives a high per cent recovery of malonaldehyde which is associated with rancidity in nut meat products. Heating an aliquot of the distillate in an acetic acid solution of 2-thiobarbituric acid yields an intense red color with a maximum absorbance at about 532 nm. As little as 0.1 μg malonaldehyde/ml can be measured. Nuts judged to be slightly rancid by a taste panel showed the presence of approximately 40 μg malonaldehyde/g nul meat. Recoveries of malonaldehyde added to samples ranged from 92 to 97%. No malonaldehyde was detected in fresh nut meats.


1974 ◽  
Vol 57 (4) ◽  
pp. 796-800 ◽  
Author(s):  
Lewis J Frauenfelder

Abstract A chromatographic-colorimetric method has been developed for the determination of trace amounts of polyvinylpyrrolidone (PVP) and its copolymers in foods, beverages, laundry products, and cosmetics. Products containing the PVP are passed through a chromatographic column and the PVP is adsorbed at the top of the column. The column is prepared from silica gel if the sample is soluble in 40% acetic acid solution while Micro-Cel E is used when the sample is soluble in a 50% ethanol solution. The PVP adsorbed on the column is then treated with Vital Red dye and the PVP-dye complex thus formed is eluted with TV-methyl pyrrolidone and measured colorimetrically. From the data obtained it is apparent that the method can detect as little as 0.1 ppm with a reproducibility of ±5% of the amount present.


Author(s):  
Dat Nguyen Thanh ◽  
Hong Hanh Nguyen Thi ◽  
Thu Dam Thi ◽  
Thuy Chu Thi ◽  
Nuong Hoang Thi ◽  
...  

An HPLC-UV method was proposed in order to determine Rutin in Sophora japonica L. extract samples (3 samples extracted with 30% ethanol, 3 samples extracted with 70% ethanol and 3 samples extracted with water). The chromatographic conditions were: Agilent Zorbax Eclipse XDB C18 Column (150 x 4.6 mm, 5 µm); UV-Vis detector (257 nm); mobile phase: a mixture of methanol and 1% acetic acid solution (40:60, v/v). The linear range was of 4.97 - 298.47µg/mL; the LOQ was of 0.205 µg/mL and the accuracy was within 99.87% - 102.3%. The method was proved to be suitable for the determination of Rutin in Sophora japonica L. extracts. Rutin content in samples varied from 30.14% to 38.67%.


1962 ◽  
Vol 8 (6) ◽  
pp. 592-592 ◽  
Author(s):  
Kurt M Dubowski

Abstract Since publication of the above paper, we have found that a procedure similar to the one described for determination of aldosaccharides in body fluids using o-toluidine in glacial acetic acid solution was described by Eric Hultman in Nature183, 108 (1959). A modification of Hultman's procedure has recently been described by A. Hyvärinen and E. A. Nikkilä in Clin. Chim. Acta7, 140 (1962). The omission of reference to Dr. Hultman's paper was entirely unintentional. Our own procedure was, of course, derived entirely experimentally, based upon Dr. O. M. Forsell's suggestion to us of Mar. 13, 1960, that we should consider the use of o-toluidine as a glucose reagent; and this suggestion is properly credited in the paper as a personal communication. The papers by Hultman and by Hyvärinen and Nikkilä nicely confirm some of the significant experimental details and results of our procedure; but obviously the Hultman paper has priority with respect to this principle.


2016 ◽  
Vol 10 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Valentina Chernova ◽  
◽  
Angela Shurshina ◽  
Elena Kulish ◽  
Gennady Zaikov ◽  
...  

Some ways of estimating the values of the intrinsic viscosity of chitosan were analyzed. It was shown that the method of Irzhak and Baranov for estimating the current value of the intrinsic viscosity allows to adequately estimates the conformational state of the macromolecular coil and its degree of swelling.


2018 ◽  
Vol 69 (2) ◽  
pp. 297-299
Author(s):  
Adriana Nita ◽  
Delia Mirela Tit ◽  
Lucian Copolovici ◽  
Carmen Elena Melinte (Frunzulica) ◽  
Dana Maria Copolovici ◽  
...  

The aim of this study was to develop and validate a rapid, accurate, and exact method for the quantitative determination of famotidine in pharmaceutical products. The HPLC analyses were performed by using a mobile phase containing methanol:1% acetic acid solution=30:7 (v/v), at a flow rate of 0.4 mL/min.The total time of the method was 10 min, and the retention time of famotidine was 4.16 min. The detection was evaluated at l=267 nm. The method has been validated by using different validation parameters. The linear response of the detector for famotidine peak area was observed at concentrations ranging from 0.1 to 0.0001 mg mL-1 , resulting in a correlation coefficient of 0.99998. The values of the detection limit and of the quantification limit are 0.00048 mg mL-1 and 0.00148 mg mL-1, respectively. The method proposed allowed accurate (with a relative error of less than 2%) and precise (RSD values less than 2.0%) determination of famotidine content in pharmaceutical products and can be used for its rapid quantitative analysis.


2010 ◽  
Vol 82 (2) ◽  
pp. 251-255 ◽  
Author(s):  
H.M.P. Naveen Kumar ◽  
M.N. Prabhakar ◽  
C. Venkata Prasad ◽  
K. Madhusudhan Rao ◽  
T.V. Ashok Kumar Reddy ◽  
...  

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