scholarly journals Spectrophotometric Determination ofN-Acetyl-L-Cysteine andN-(2-Mercaptopropionyl)-Glycine in Pharmaceutical Preparations

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Lea Kukoc-Modun ◽  
Njegomir Radić
Keyword(s):  
Regression Analysis ◽  
Detection Limit ◽  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Complexation Reaction ◽  
Calibration Data ◽  
Pharmaceutical Excipients

A simple spectrophotometric method for the determination ofN-acetyl-L-cysteine (NAC) andN-(2-mercaptopropionyl)glycine (MPG) in pharmaceutical preparations was developed, validated, and used. The proposed equilibrium method is based on a coupled two-step redox and complexation reaction. In the first step, Fe(III) is reduced to Fe(II) by NAC or MPG. Subsequently, Fe(II) is complexed with 2,4,6-tripyridyl-s-triazine (TPTZ). Several analytical parameters of the method were optimized for NAC and MPG analysis in the concentration range from 1.0 μM to 100.0 μM. Regression analysis of the calibration data showed a good correlation coefficient (0.9999). The detection limit of the method was 0.14 μM for NAC and 0.13 μM for MPG. The method was successfully applied to quantify NAC and MPG in pharmaceutical preparations. No interferences were observed from common pharmaceutical excipients.

scholarly journals Spectrophotometric determination of methyldopa in pharmaceutical formulations

2005 ◽  
Vol 30 (3) ◽  
pp. 23-28 ◽  
Author(s):  
P. R. S. Ribeiro ◽  
L. Pezza ◽  
H. R. Pezza
Keyword(s):  
Correlation Coefficient ◽  
Spectrophotometric Method ◽  
Confidence Level ◽  
Low Cost ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Pharmaceutical Products ◽  
Complexation Reaction ◽  
Excellent Correlation

A new, simple, precise, rapid and low-cost spectrophotometric method for methyldopa determination in pharmaceutical preparations is described. This method is based on the complexation reaction of methyldopa with molybdate. Absorbance of the resulting yellow coloured product is measured at 410 nm. Beer's Law is obeyed in a concentration range of 50 - 200 µg ml-1 methyldopa with an excellent correlation coefficient (r = 0.9999). No interference was observed from common excipients in formulations. The results show a simple, accurate, fast and readily applied method to the determination of methyldopa in pharmaceutical products. The analytical results obtained for these products by the proposed method are in agreement with those of the Brazilian Pharmacopoeia procedure at 95% confidence level.

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).

Spectrophotometric Determination of Trace Cetyltrimethyl Ammonium Bromide by Nanosilver

2011 ◽  
Vol 356-360 ◽  
pp. 920-923 ◽  
Author(s):  
Gui Qing Wen ◽  
Yan Mei Ma ◽  
Zhi Liang Jiang
Keyword(s):  
Detection Limit ◽  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Water Samples ◽  
Ammonium Bromide ◽  
Buffer Solution ◽  
Cetyltrimethyl Ammonium Bromide ◽  
Cetyltrimethyl Ammonium

The decolored reaction between cetyltrimethyl ammonium bromide (CTMAB) and nanosilver was studied, and a simple, rapid spectrophotometric method was established to determine CTMAB. In pH 7.8 Na2HPO4-NaH2PO4buffer solution, nanosilver exhibited a maximum absorption peak at 395 nm, and it reacted with CTMAB to form larger particles that resulted in the absorption decreasing. Under the chosen conditions, the decreased absorbance was linear to the CTMAB concentration in the range of 2.5×10-7-1.0×10-5mol/L, with the regression equation of ΔA395 = 0.0431C CTMAB + 0.0182, the correlation coefficient of 0.9968 and the detection limit of 0.21μmol/L CTMAB. The proposed method was applied to detect CTMAB in water samples, with simplicity, rapidity and accuracy.

scholarly journals DETERMINATION OF TRACE NITRITE AS 4-(4-NITROBENZENAZO)- 1-AMINONAPHTHALENE COMPLEX BY EXTRACTION-SPECTROPHOTOMETRY

2010 ◽  
Vol 9 (2) ◽  
pp. 254-260
Author(s):  
Choirul Amri ◽  
Dwi Siswanta ◽  
Mudasir Mudasir
Keyword(s):  
Detection Limit ◽  
Organic Solvents ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Absorbance Unit ◽  
Extraction Spectrophotometry ◽  
Linear Concentration

A study of extraction-spectrophotometric method for the determination of trace nitrite as 4-(4-nitrobenzenazo)-1-aminonaphthalene complex using n-amylalcohol and chloroform as organic solvents has been done. Results of the study showed that extraction-spectrophotometric determination of nitrite using n-amylalcohol or chloroform was very sensitive and had low limit of detection. Extraction-spectrophotometric method of nitrite using n-amylalcohol gave range of linear concentration 0.000-0.054 mg/L NO2--N, detection limit of 2.09x10-4 mg/L NO2--N, and sensitivity of 34.514 ± 0.398 absorbance unit per mg/L of NO2--N. Meanwhile, extraction-spectrophotometric of nitrite using chloroform had range of linear concentration of 0.000-0.100 mg/L NO2--N, detection limit of 8.99x10-4 mg/L NO2--N, and sensitivity of 18.353 ± 0.456 absorbance unit per mg/L NO2--N.   Keywords: Nitrite Trace, 4-(4-Nitrobenzenazo)-1-Aminonaphthalene, Extraction-Spectrophotometry

scholarly journals Spectrophotometric Determination of Epinephrine in Pharmaceutical Preparations Using Praseodymium as Mediating Metals

2011 ◽  
Vol 8 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Relative Error ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Direct Methods ◽  
Orange Yellow ◽  
Sensitive Spectrophotometric Method

A simple, accurate and sensitive spectrophotometric method for the determinaion of epinephrine is described . The method is based on the coordination of Pr (III) with epinephrine at pH 6. Absorbance of the resulting orange yellow complex is measured at 482 nm . A graph of absorbance versus concentrations shows that beer 's low is obeyed over the concentration range (1-50)mg.ml-1 of epinephrine with molar absorpitivity of ( 2.180x103 L.mol-1.cm-1 ), a sandell sensitivity of (0.084 mg.cm-2 ), a relative error of (-2.83%) , a corrolation coffecient (r= 0.9989) and recovery % ( 97.03 ± 0.75 ) depending on the concentration.This method is applied to analyse EP in several commercially available pharmaceutical preparations using direct methods .All statistical calculations are implemented via a Minitab software version 11.

Improved Spectrophotometric Determination of Cyclopiazonic Acid in Poultry Feed and Corn

1990 ◽  
Vol 73 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Ivan Chang-Yen ◽  
Keshore Bidasee
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Cyclopiazonic Acid ◽  
Poultry Feed ◽  
Reaction Conditions ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Feed Samples

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.

A new optical sensor for spectrophotometric determination of uranium (VI) and thorium (IV) in acidic medium

2017 ◽  
Vol 105 (12) ◽  
Author(s):  
O. A. Elhefnawy
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Optical Sensor ◽  
Acidic Medium ◽  
Complexation Reaction

AbstractA spectrophotometric method was developed for U(VI) and Th(IV) determination in acidic medium by using proposed optical sensor. This sensor is base on the complexation reaction of the ionophore midodrine hydrochloride (

Spectrophotometric Determination of Isocarboxazid Bulk Drug and Tablets by Reaction with/7-Dimethylaminocinnamaldehyde

1988 ◽  
Vol 71 (6) ◽  
pp. 1134-1136
Author(s):  
Michael E El-Kommos
Keyword(s):  
Regression Analysis ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Trichloroacetic Acid ◽  
Excellent Correlation ◽  
Electrophilic Attack ◽  
Reagent Ratio ◽  
Bulk Drug ◽  
Methanolic Medium

Abstract A Spectrophotometric Method Is Described For The Determination Of Isocarboxazid. The Method Is Based On The Reaction Of The Drug With p-Dimethylaminocinnamaldehyde In The Presence Of Trichloroacetic Acid In A Methanolic Medium To Produce A Very Intense Red Chromophore (ℷmax = 500 Nm, Emax= 1.05 X 105). The Reaction Is Proposed To Proceed Via Electrophilic Attack At The C-4 Position Of The Isoxazole Nucleus. Job's Plot Indicated A 1:1 Drug-To-Reagent Ratio. Regression Analysis Of Beer's Plot Showed Excellent Correlation (R = 0.9996) In The Concentration Range 0.25-2.10 Fig Isocarboxazid/Ml. The Developed Color Is Stable For At Least 12 H. Results Of Analyses Of Bulk Drug And Tablets By The Proposed Method Are Comparable To Those For Usp Xxi Methods.

Atomic Absorption Spectrophotometric Determination of Aluminum in Pharmaceuticals

1973 ◽  
Vol 56 (2) ◽  
pp. 358-360
Author(s):  
Pramod P Karkhanis ◽  
Jon R Anfinsen
Keyword(s):  
Atomic Absorption ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Distinct Advantage ◽  
Commercial Products

Abstract A simple, sensitive, and rapid atomic absorption spectrophotometric method for aluminum in pharmaceutical preparations is described. No interference from other ingredients has been experienced in utilizing this technique. The reproducibility of the method has been reported for a lotion containing lipid base. The results of the determination of aluminum in 3 different commercial products are presented. This method, because of its simplicity and sensitivity, provides a distinct advantage over methods previously reported in the literature.

scholarly journals Spectrophotometric Determination of Famciclovir and Racecodotril Using 2, 6-Dichloroquinone–Chlorimide

2007 ◽  
Vol 4 (1) ◽  
pp. 50-52 ◽  
Author(s):  
M. Vamsi Krishna ◽  
P. V. Madhavi Latha ◽  
D. Gowri Sankar
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Oxidative Coupling ◽  
Pharmaceutical Preparations ◽  
Coupling Product ◽  
Beer's Law ◽  
Beer’S Law ◽  
Sensitive Spectrophotometric Method

A simple, sensitive spectrophotometric method for the determination of Famciclovir and Racecodotril is developed. It is based on the formation of a colored oxidative coupling product between 2,6-dichloroquinone-chlorimide and the drug is described. The method has been extended to pharmaceutical preparations. The absorption maxima and Beer’s law limits for Famciclovir are 500 nm, 20-100 µg/mL and for Racecodotril are 460 nm, 12.5-62.5 µg/mL.

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