scholarly journals Pitting Corrosion on Diamond-like Carbon Films to High Concentration Sodium Hydroxide Solution

2017 ◽  
pp. 827
Author(s):  
Klimenko Lina Yu ◽  
Slabiak Oksana I ◽  
Ivanchuk Iryna M ◽  
Tokaryk Galyna V ◽  
Kolisnyk Iuliia S

Efavirenz is a non-nucleoside reverse transcriptase inhibitor and attributed to the group of antiretroviral medicines used for treatment of HIV infection. For efavirenz determination the method of HPLC is widely used, but efavirenz is applied in high concentration and less sensitive methods of analysis such as spectrophotometry may be useful for its quantification. The aim is to develop UV-spectrophotometric procedures of efavirenz quantification and carry out step-by-step validation of the developed procedures. UV-spectra of efavirenz in 96% ethanol and 0.1 M sodium hydroxide solution have been investigated and the absorption maximums are observed at 247 nm and 267 nm respectively. The procedures of efavirenz quantitative determination by the method of UV-spectrophotometry have been developed using the mentioned solvents and wavelengths respectively. Their validation by such parameters as stability, linearity, accuracy and precision in the variants of the method of calibration curve, method of standard and method of additions has been carried out. All procedures of efavirenz quantitative determination are acceptable for application. The best linearity, accuracy and repeatability have been fixed for the procedure with application of 0.1 M sodium hydroxide solution as a solvent in the variant of the method of additions.


1982 ◽  
Vol 35 (8) ◽  
pp. 1727 ◽  
Author(s):  
J Rosevear ◽  
JFK Wilshire

The sodium salt of 4-amino-3-nitrobenzenesulfonic acid (O-nitroaniline-p-sulfonic acid) has been prepared by the action of dilute sodium hydroxide solution on ethyl [(4-chlorosulfonyl-2-nitro)- phenyllcarbamate. Central to this synthesis is the finding that the N-ethoxycarbonyl group, when located ortho to a nitro group (but not to a bromo group), is readily removed by dilute sodium hydroxide solution.


2015 ◽  
Vol 22 (12) ◽  
pp. 4545-4550 ◽  
Author(s):  
Chong-qing Wang ◽  
Hui Wang ◽  
Guo-hua Gu ◽  
Jian-gang Fu ◽  
You-nian Liu

1997 ◽  
Vol 1997 (Supplement94) ◽  
pp. 217-225
Author(s):  
Tatsuya Fujiyoshi ◽  
Hiroyuki Masuda ◽  
Tokuji Nishinaka ◽  
Tetsuo Futami ◽  
Hiromi Shibuya

Author(s):  
CLAUDIO LIMA AGUIAR ◽  
TOBIAS J. B. MENEZES

Avaliou-se a produção de celulases e xilanase de Aspergillus niger IZ9, crescido sobre bagaço de cana, quimicamente tratado, como substrato. Os tratamentos foram: solução de hidróxido de sódio a 4%, e solução de hidróxido de sódio a 4%, ácido fosfórico p.a. e vapor. A produção das enzimas celulolíticas (celulase total, endoglicanase e ­glicosidase) e xilanase foi observada nos bagaços tratados e nãotratado. O tratamento com solução de hidróxido de sódio a 4% promoveu maior indução de síntese da maioria das enzimas, com exceção de ­glicosidase, a qual apresentou produção semelhante para os bagaços tratados quimicamente. Abstract It was evaluated the production of cellulases and xylanase by Aspergillus niger IZ09 grown in a substrate consisted of chemically treated sugarcane bagasse. The treatments were: 4% sodium hydroxide solution and 4% sodium hydroxide solution, phosphoric acid and steam. The production of the cellulolytic enzymes (total cellulase, endoglycanase and B.CEPPA, Curitiba, v. 18, n. 1, jan./jun.2000 67 ­glucosidase) and xylanase was observed in the treated and nontreated bagasses. The treatment with 4% sodium hydroxide solution promoted a greater induction of the synthesis of the majority of the enzymes, with exception of ­glucosidase, which showed similar production for both chemically treated bagasses.


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