Indirect Determination of Methimazole in Pharmaceutical Sample by Discoloration Spectrophotometry Using Fe (III)-Tiron System

2013 ◽  
Vol 781-784 ◽  
pp. 115-119 ◽  
Author(s):  
Chang Qing Tu ◽  
Xin Rong Wen
Keyword(s):  
Linear Regression ◽  
Linear Relationship ◽  
Correlation Coefficient ◽  
Linear Correlation ◽  
Effect Factors ◽  
Indirect Determination ◽  
Pharmaceutical Sample ◽  
Novel Method ◽  
Maximum Absorption Wavelength

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.

Indirect Spectrophotometric Determination of Methimazole Using Phenanthroline-Fe(II)

2013 ◽  
Vol 634-638 ◽  
pp. 101-105 ◽  
Author(s):  
Xin Rong Wen ◽  
Chang Qing Tu
Keyword(s):  
Linear Regression ◽  
Linear Relationship ◽  
Acid Medium ◽  
Correlation Coefficient ◽  
Linear Correlation ◽  
Effect Factors ◽  
Indirect Determination ◽  
Novel Method ◽  
Maximum Absorption Wavelength

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.

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
Keyword(s):  
Linear Regression ◽  
Linear Relationship ◽  
Spectrophotometric Determination ◽  
Linear Correlation ◽  
Effect Factors ◽  
Reaction Conditions ◽  
Pharmaceutical Sample ◽  
Novel Method ◽  
Maximum Absorption Wavelength

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.

Spectrophotometric Determination of 6-Mercaptopurine in Pharmaceutical Sample Using Fe(III)-Potassium Ferricyanide System

2014 ◽  
Vol 881-883 ◽  
pp. 479-483 ◽  
Author(s):  
Chang Qing Tu ◽  
Xin Rong Wen
Keyword(s):  
Linear Regression ◽  
Linear Relationship ◽  
Prussian Blue ◽  
Linear Correlation ◽  
Potassium Ferricyanide ◽  
Effect Factors ◽  
Inexpensive Method ◽  
Pharmaceutical Sample ◽  
Maximum Absorption Wavelength

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.

scholarly journals Spectrophotometric Determination of Methimazole by Silicomolybdenum Blue

2018 ◽  
Vol 53 ◽  
pp. 01046
Author(s):  
Xinrong Wen ◽  
Changqing Tu
Keyword(s):  
Linear Regression ◽  
Linear Relationship ◽  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Linear Correlation ◽  
Reaction Conditions ◽  
Optimum Reaction ◽  
Novel Method ◽  
Maximum Absorption Wavelength

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.

scholarly journals Determination of Isoniazid by Fe(II)-2,2’-Bipyridine Spectrophotometry

2021 ◽  
Vol 290 ◽  
pp. 01028
Author(s):  
Changqing Tu ◽  
Xinrong Wen
Keyword(s):  
Linear Regression ◽  
Linear Relationship ◽  
Correlation Coefficient ◽  
Linear Correlation ◽  
Mass Concentration ◽  
Linear Regression Equation ◽  
Optimum Conditions ◽  
Acidic Media ◽  
Maximum Absorption Wavelength

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.

scholarly journals Determination of Cysteine by Discoloration Spectrophotometry using Copper(II)-Bis-Cyclohexanone Oxalydihydrazone

2021 ◽  
Vol 245 ◽  
pp. 03023
Author(s):  
Changqing Tu ◽  
Xinrong Wen
Keyword(s):  
Linear Relationship ◽  
Correlation Coefficient ◽  
Influencing Factors ◽  
Alkaline Medium ◽  
Linear Correlation ◽  
Mass Concentration ◽  
New Method ◽  
Chromogenic Reagent ◽  
Maximum Absorption Wavelength

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.

Indirect Determination of Acetylcysteine in Pharmaceutical Sample by Discoloration Spectrophotometry Using Fe(III)-Tiron System

2015 ◽  
Vol 713-715 ◽  
pp. 2710-2713
Author(s):  
Chang Qing Tu ◽  
Xin Rong Wen
Keyword(s):  
Spectrophotometric Method ◽  
Indirect Determination ◽  
Chromogenic Reagent ◽  
Pharmaceutical Sample

Fe (Ш) can be reduced to Fe (II) by hydrosulfuryl (-SH) in acetylcysteine molecule,and then using tiron as chromogenic reagent of Fe (Ш),and the content of acetylcysteine is determinated indirectly through determinating the surplus content of Fe (Ш) in the system.An accurate fast spectrophotometric method for the determination of acetylcysteine by discoloration spectrophotometry using Fe (Ш)-tiron system has been established.This proposed method had been successfully applied to determinate of acetylcysteine in real pharmaceutical.

scholarly journals IDENTIFICATION, QUANTIFICATION AND VALIDATION OF STIGMASTEROL FROM ALPINIA CALCARATA USING HIGH-PERFORMANCE THIN LAYER CHROMATOGRAPHY METHOD

2017 ◽  
Vol 9 (9) ◽  
pp. 126
Author(s):  
Pratheema Philomindoss
Keyword(s):  
Linear Regression ◽  
Thin Layer ◽  
Linear Relationship ◽  
High Performance ◽  
Retention Factor ◽  
Chromatography Method ◽  
Ich Guidelines ◽  
Layer Chromatography ◽  
Hptlc Method

Objective: The present study is designed to develop a new simple, precise, rapid and selective high‐performance thin‐layer chromatographic (HPTLC) method for the determination of stigmasterol in methanolic rhizomes extract of Alpinia calcarata.Methods: As per International Conference on Harmonization (ICH) guidelines we have applied different concentrations of stigmasterol as standard on HPTLC plates for the quantification of stigmasterol from the Alpinia calcarata rhizomes. The concentration of standard stigmasterol is 1 mg/ml.Results: The retention factor of stigmasterol was 0.58. Linearity was obtained in the range of 50 ng‐250 ng for stigmasterol. The developed and validated HPTLC method was employed for stigmasterol in methanolic rhizomes extract of Alpinia calcarata for standardization of the content of the marker. The linear regression data for the calibration plots showed a good linear relationship with r=0.99977 for stigmasterol, respectively Satisfactory recoveries of 99.77 % were obtained for stigmasterol.Conclusion: The results obtained in validation assays indicate the accuracy and reliability of the developed HPTLC method for the quantification of stigmasterol in methanolic rhizomes extract of Alpinia calcarata

Indirect determination of chlorophenols by atomic absorption spectrometry (AAS) after extraction of their ionic associates involving the dipyridylocopper(II) or phenanthrolinocopper(II) complex

1991 ◽  
Vol 56 (12) ◽  
pp. 2827-2832
Author(s):  
Václav Stužka ◽  
Jana Krejčí
Keyword(s):  
Methyl Isobutyl Ketone ◽  
Absorption Spectrometry ◽  
Methyl Isobutyl ◽  
Isobutyl Ketone ◽  
Single Extraction ◽  
Indirect Determination ◽  
Complete Extraction ◽  
Ionic Associates ◽  
Novel Method

A novel method was developed for the indirect determination of chlorophenols by AAS after extraction of their ionic associates involving the dipyridylocopper(II) (CuDP) or phenanthrolinocopper(II) (CuPH) complex into nitrobenzene, o-dichlorbenzene or methyl isobutyl ketone. Nitrobenzene appeared to be particularly suitable for the extraction of the CuDP associate, methyl isobutyl ketone, for the extraction of the CuPH associate. Thee method is applicable to chlorophenol concentrations of 10-6 to 10-7 mol l-1. Using CuDP after a single complete extraction into 10 ml of nitrobenzene, the lowest determinable concentration giving rise to absorbance A = 0.010 is 0.3 mg of pentachlorophenol in a litre; using CuPH after a single extraction into 10 ml of methyl isobutyl ketone, it is 0.2 mg of chlorophenol in a litre.

Spectrophotometric Determination of Al(III) in Environment Water with p-Carboxyarsenazo

2013 ◽  
Vol 830 ◽  
pp. 363-366 ◽  
Author(s):  
Lin Gao ◽  
Bo Yan ◽  
Fang Chen ◽  
Jun Long Yao
Keyword(s):  
Detection Limit ◽  
Linear Regression ◽  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Water Samples ◽  
High Sensitivity ◽  
Molar Absorptivity ◽  
Linear Regression Equation ◽  
Color Reagent

Spectrophotometry determination of Al (III) with new color reagent p-Carboxyarsenazo(CAA) was reported, and the chromomeric reaction between CAA and Al (III) was studied. In a buffer medium of pH=4.6 HAc-NaAc, CAA reacts with Al (III) to form a red complex and exhibits an absorption maxima at 614nm; Beer,s law is obeyed for 0.10~0.80 μg/mL of Alumium in color solution, the color reaction exhibited high sensitivity (the apparent molar absorptivity obtained is 1.61×104 L/(mol.cm)), and the absorbance fit linear regression equation is A=0.0105+0.561X(μg/mL), the correlation coefficient is 0.9998, the detection limit of the method is 0.36 μg/L. The results obtained by this method in the determination of environment water samples were rapid, accurate and satisfactorily.

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