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.

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.

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.

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.

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.

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.

Determination of Sucralose by Controlled UV Photodegradation Followed by UV Spectrophotometry

2013 ◽  
Vol 96 (3) ◽  
pp. 603-606
Author(s):  
Mohd Idris ◽  
V Jayathirtha Rao ◽  
Deepak Middha ◽  
Sudhir Kumar Shukla ◽  
Tulsidas Ramachandra Rao Baggi
Keyword(s):  
Correlation Coefficient ◽  
Alkaline Medium ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Artificial Sweeteners ◽  
Uv Spectrophotometry ◽  
Medium Ph ◽  
Accuracy And Precision ◽  
Uv Photodegradation

Abstract A simple and time-efficient UV spectrophotometric method was developed for the determination of sucralose in artificial sweeteners. The procedure is based on the UV spectrophotometric determination of the photodegraded product at 270 nm in alkaline medium (pH 12). LOD for this method was 0.02 g/L, and the calibration curve was found to obey Beer's law in the concentration range of 0.1 to 1.2 g/L, with a correlation coefficient (R2) value of 0.9977. The proposed method was studied for accuracy and precision.

scholarly journals Isolation and Identification of Catechin by a New Method from Food Efficiency Stimulating Plant Alhagi camelorum

2017 ◽  
Vol 60 (2) ◽  
pp. 59-66
Author(s):  
Abdul Hafeez Laghari ◽  
Shahabuddin Memon ◽  
Aisha Nelofar ◽  
Khalid Mohammad. Khan
Keyword(s):  
Antioxidant Capacity ◽  
Simultaneous Determination ◽  
Present Article ◽  
Linear Correlation ◽  
Detection System ◽  
New Method ◽  
Isolation And Identification ◽  
Real Samples ◽  
Dual Detection

The present article describes a new developed method for the simultaneous determination of(+)-catechin (1) and (-)-epicatechin (2), separated via HPLC. The method has been validated and appliedon the real samples and 1 has been detected in both aerial and root parts of Alhagi camelorum without anyambiguity of fake positive or negative presence of 1 or 2 by virtue of dual detection system of UV andMass Spectrometry. The antioxidant capacity was also investigated and a linear correlation has been noticedbetween the antioxidant capacity and the catechin amount in A. camelorum extracts

scholarly journals A new method to determine the reproductive condition in female tubeworms tested in Seepiophila jonesi (Polychaeta: Siboglinidae: Vestimentifera)

2008 ◽  
Vol 88 (5) ◽  
pp. 909-912 ◽  
Author(s):  
Ana Hilário ◽  
Paul A. Tyler ◽  
David W. Pond
Keyword(s):  
Linear Relationship ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Gonad Development ◽  
New Method ◽  
Wax Ester ◽  
Cold Seeps ◽  
Reproductive Condition ◽  
The Individual

Vestimentiferan tubeworms are significant members of deep-sea chemosynthetically-driven communities, including hydrothermal vents and cold seeps. The reproductive condition in this taxon is rarely studied because of sampling constraints inherent to these environments, and the lack of a simple methodology to quantify gonad development in vestimentiferans.We demonstrate that the amount of gonad found in the first 10 mm of trunk can be used as representative of the reproductive condition of the individual, and we establish a linear relationship between the amount of gonad and the proportion of wax ester in the trunk of female vestimentiferans. This relationship represents a new method for the determination of the reproductive condition in this group.

scholarly journals Spectrophotometric determination of Valsartan in pure form and in its pharmaceutical preparations

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Qabas Rashid ◽  
Ruwaida Farman Salih
Keyword(s):  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Chromogenic Reagent

An easy, rapid and economical spectrophotometric method for  determination of  Valsartan (Val), by reaction with 4-chloro-7-nitrobenzofurazan (NBD-Cl) as reagent in an alkaline interemediate. This method is based on the forming of product between (Val) and the chromogenic reagent (NBD-Cl), to produce a brown color at (pH 11.9) and λmax. 470 nm.  Beer’s Law is obeyed at the concentrations range of (0.4-14.8 µg/ml), with molar absorptivity of (1.05×104 L/mol.cm) and correlation coefficient 0.9827, The limit of detection was 0.557 µg/ml. The suggested method was prosperity implement to the determination of (Val) in  pure form and in its pharmaceutical formulations (tablets).

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