Spectrophotometric Determination of Isoniazid in Pharmaceutical Sample by Silicomolybdenum Blue

2014 ◽  
Vol 1033-1034 ◽  
pp. 548-551
Author(s):  
Xin Rong Wen ◽  
Chang Qing Tu

A novel method for the spectrophotometric determination of isoniazid by silicomoly- bdenum blue has been established.The various effect factors on the spectrophotometric determination of isoniazid by silicomolybdenum blue were investigated in detail.The results showed that under certain reaction conditions,silicomolybdenum yellow could be reduced to silicomolybdenum blue by isoniazid, and the content of isoniazid was determinated indirectly through determinating the absorbance of the silicomolybdenum blue. The maximum absorption wavelength of chromogenic system is 740 nm, good linear relationship is obtained between the absorbance and the concentration of isoniazid in the range of 1.968~27.55 μg/mL,and the equation of the linear regression is A=0.0247+61.824ρ (μg/mL) with a linear correlation coefficient is 0.9995.This proposed method has been successfully applied to determinate of isoniazid in isoniazid tablets, and the results agree well with those obtained by pharmacopoeial method.

2013 ◽  
Vol 781-784 ◽  
pp. 115-119 ◽  
Author(s):  
Chang Qing Tu ◽  
Xin Rong Wen

A novel method for the indirect determination of methimazole by discoloration spectrophotometry using Fe (Ш)-tiron system has been established.The various effect factors on the determination of methimazole by discoloration spectrophotometry using tiron-Fe (Ш) system were investigated in detail. The results showed that by controlling pH=2.8,Fe (Ш) could be reduced to Fe (II) by hydrosulfuryl (-SH) in methimazole molecule,and then using tiron as chromogenic reagent of Fe (Ш),and the content of methimazole was determinated indirectly through determinating the surplus content of Fe (Ш) in the system.The maximum absorption wavelength of chromogenic system was 663 nm, good linear relationship was obtained between A and the concentration of methimazole in the range of 3.2~12.8μg·mL-1,the equation of the linear regression was A=-0.1849+57.277ρ (mg·mL-1),with a linear correlation coefficient was 0.9998.This proposed method had been successfully applied to determinate of methimazole in real pharmaceutical.


2018 ◽  
Vol 53 ◽  
pp. 01046
Author(s):  
Xinrong Wen ◽  
Changqing Tu

Under optimum reaction conditions, Ammonium silicomolybdate could be quantitatively reduced to silicomolybdenum blue by hydrosulfuryl(-SH) in methimazole molecule, and the content of methimazole was determinated indirectly through determinating the absorbance of the silicomolybdenum blue. A novel method for the spectrophotometric determination of methimazole by silicomolybdenum blue has been established. The results showed that the maximum absorption wavelength of silicomolybdenum blue is 730 nm, good linear relationship is obtained between the absorbance of silicomolybdenum blue and the concentration of methimazole in the range of 8.000-160.0μg/mL, and the equation of the linear regression is A=0.0757+11.547ρ (mg/mL) with a linear correlation coefficient is 0.9998. This proposed method has been applied to determinate of methimazole in tablets, and the results agree well with those obtained by pharmacopoeial method.


2013 ◽  
Vol 634-638 ◽  
pp. 101-105 ◽  
Author(s):  
Xin Rong Wen ◽  
Chang Qing Tu

A novel method for the indirect determination of methimazole by spectrophotometry using phenanthroline-Fe(Ⅱ) has been established.The results showed that in acid medium, Fe(Ш) could be reduced to Fe(Ⅱ) by hydrosulfuryl(-SH) in methimazole molecule,and then using phenanthroline as chromogenic reagent of Fe(Ⅱ), and the content of methimazole was determinated indirectly through determinating the content of Fe(Ⅱ) by spectrophotometry. The various effect factors on the determination of methimazole by spectrophotometry using phenanthroline-Fe(Ⅱ) were investigated in detail.The maximum absorption wavelength of chromogenic system was 509 nm, good linear relationship was obtained between the absorbance and the concentration of methimazole in the range of 0.0016~0.0064 mg/mL,the equation of the linear regression was A = 0.1942 + 64.598ρ (mg•mL-1),with a linear correlation coefficient was 0.9995.This proposed method had been applied to determinate of methimazole in real pharmaceutical,and the results agreed well with those obtained by pharmacopoeial method.


2014 ◽  
Vol 881-883 ◽  
pp. 479-483 ◽  
Author(s):  
Chang Qing Tu ◽  
Xin Rong Wen

In the present work,we developed a simple,fast,sensitive and inexpensive method to determine 6-mercaptopurine (6-MP) in pharmaceutical sample using Fe (III)-potassium ferricyanide system by spectrophotometry.The results show that in acid medium, Fe (Ш) can be reduced to Fe (II) by hydrosulfuryl (-SH) in 6-Mercaptopurin molecule, and then Fe (II) reacts with potassium ferricyanide to form a soluble Prussian blue (KFeIII[FeII(CN)6]),the content of 6-MP was determinated indirectly through determinating the absorbance of the soluble Prussian blue.The various effect factors on the determination of 6-MP by spectrophotometry using potassium Fe (III)-ferricyanide system were investigated in detail.The maximum absorption wavelength of chromogenic system was 755 nm, good linear relationship was obtained between the absorbance and the concentration of 6-MP in the range of 0.4120~2.884 μ g·/mL,the equation of the linear regression was A=0.0411+0.1462C (μ g·/mL),with a linear correlation coefficient was 0.9991.This proposed method had been successfully applied to determinate of 6-MP in real pharmaceutical,and the results agreed well with those obtained by pharmacopoeial method.


2021 ◽  
Vol 290 ◽  
pp. 01028
Author(s):  
Changqing Tu ◽  
Xinrong Wen

In acidic media, Fe(Ш) could be reduced to Fe(Ⅱ) by isoniazid, Fe(Ⅱ) reacts with 2,2'-bipyridine to form an orange complex with a maximum absorption wavelength of 522 nm. According to this principle, the content of isoniazid can be measured indirectly by measuring the amount of Fe(Ⅱ). A new method for the determination of isoniazid by Fe(Ⅱ)-2,2'-bipyridine spectrophotometry has been established. At the optimum conditions, the linear relationship is good between the mass concentration of isoniazid and absorbance of Fe(Ⅱ)-2,2'-bipyridine complex in the range of 0.0004000-0.002800 mg/mL. The linear regression equation is A=0.0251+138.04C(mg/mL), and the linear correlation coefficient is 0.9995. This method is used to determine the content of isoniazid in isoniazid tablets, and the results are similar to those obtained by pharmacopoeia method.


2021 ◽  
Vol 245 ◽  
pp. 03023
Author(s):  
Changqing Tu ◽  
Xinrong Wen

In the alkaline medium of pH=9.18, Cu2+ can be reduced to Cu+ by the sulfhydryl (-SH) of cysteine, and it result in the decrease the amount of Cu2+ in the system. The decrement of Cu2+ is directly proportional to the addition of cysteine, then using bis-cyclohexanone oxalyldihydrazone (BCO) as chromogenic reagent for Cu2+ to determinate the content of cysteine indirectly by discoloration spectrophotometry. A new method for the determination of cysteine by discoloration spectrophotometry using Copper(II)-BCO has been established. The influencing factors of the determination of cysteine is investigated. The results show that the maximum absorption wavelength of chromogenic system was 602 nm, in the range of 0.008000~0.06800 mg/mL, the linear relationship between the decrease of absorbance and the mass concentration of methimazol is A=0.2162+2.4824C (mg/mL), and the linear correlation coefficient is r=0.9959. The method has been applied to the determination of cysteine in food, and the results are basically consistent with those determined by pharmacopoeial method.


2013 ◽  
Vol 726-731 ◽  
pp. 1453-1456
Author(s):  
Ai Hui Liang ◽  
Jing Peng ◽  
Yuan Li ◽  
Ling Ling Ye ◽  
Gui Qing Wen

In the presence of NaOH, glucose hydrolyze and polymerize to generate yellow carbon nanoparticles that had an absorption peak at 336 nm. Under the selected conditions, result showed the concentration of glucose have a good linear relationship between absorbance value and glucose concentration in the range of 0.0005-0.060 mol/L. This method has been used for the assay of glucose injection sample, with simplicity, rapidity, and accuracy.


1981 ◽  
Vol 27 (1) ◽  
pp. 144-146 ◽  
Author(s):  
W S Robertson

Abstract Some modifications of the conditions of the reaction between plasma and bromcresol green have led to an improved method for determination of plasma albumin with the Vickers M300 multichannel analyzer. Dye concentration and reaction time are the factors principally influencing method specificity, but variable protein composition of human plasma also affects it, so that optimal reaction conditions vary from specimen to specimen. Thus a compromise must be reached such that the best conditions for determining plasma albumin over a range of different protein concentrations are achieved. In the proposed method for the Vickers M300 a reaction time of 12 s (the minimum possible) is used. Comparison with "rocket" immunoelectrophoresis gave the following linear regression: y = 10 + 0.79 x (n = 91; r = 0.96).


1990 ◽  
Vol 73 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Ivan Chang-Yen ◽  
Keshore Bidasee

Abstract An improved visible spectrophotometric method has been developed for cyclopiazonic acid in poultry feed and corn. The method Is based on the reaction of cyclopiazonic acid with Ehrlich reagent and detection at 580 nm. Reaction conditions were optimized with respect to reaction and measurement times and acid and Ehrlich reagent concentrations. Calibration curves were linear from 1 to 20 μg cyclopiazonic acid in 3 mL Ehrlich reagent, with a lower detection limit of 0.08 mg/kg for 50 g samples of poultry feed and corn. Recoveries from 50 g samples of poultry feed spiked with cyclopiazonic ranging from 0.16 to 1.20 mg/kg averaged 93.8%. Moldy corn and poultry feed samples analyzed by this method contained between 1 and 4 mg/kg cyclopiazonic acid.


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