scholarly journals A New Kinetic Spectrophotometric Method for the Quantitation of Amorolfine

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
César Soto ◽  
Cristian Poza ◽  
David Contreras ◽  
Jorge Yáñez ◽  
Fallon Nacaratte ◽  
...  
Keyword(s):  
Spectrophotometric Method ◽  
Tap Water ◽  
Fixed Time ◽  
Fungal Cell ◽  
Inhibition Of Growth ◽  
Fungicide Activity ◽  
Dual Inhibition ◽  
Assay Precision ◽  
Kinetic Spectrophotometric

Amorolfine (AOF) is a compound with fungicide activity based on the dual inhibition of growth of the fungal cell membrane, the biosynthesis and accumulation of sterols, and the reduction of ergosterol. In this work a sensitive kinetic and spectrophotometric method for the AOF quantitation based on the AOF oxidation by means of KMnO4at 30 min (fixed time), pH alkaline, and ionic strength controlled was developed. Measurements of changes in absorbance at 610 nm were used as criterion of the oxidation progress. In order to maximize the sensitivity, different experimental reaction parameters were carefully studied via factorial screening and optimized by multivariate method. The linearity, intraday, and interday assay precision and accuracy were determined. The absorbance-concentration plot corresponding to tap water spiked samples was rectilinear, over the range of 7.56 × 10−6–3.22 × 10−5 mol L−1, with detection and quantitation limits of 2.49 × 10−6 mol L−1and 7.56 × 10−6 mol L−1, respectively. The proposed method was successfully validated for the application of the determination of the drug in the spiked tap water samples and the percentage recoveries were 94.0–105.0%. The method is simple and does not require expensive instruments or complicated extraction steps of the reaction product.

scholarly journals New Kinetic Spectrophotometric Method for Determination of Folic Acid in Pharmaceutical Formulations

2015 ◽  
Vol 50 ◽  
pp. 169-178
Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal
Keyword(s):  
Folic Acid ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Fixed Time ◽  
Rate Data ◽  
Sulfuric Acid Medium ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results

A simple and sensitive kinetic spectrophotometric method has been developed for the determination of folic acid (FA) in bulk and pharmaceutical Formulations. The method is based on the oxidation of FA by Fe (III) in sulfuric acid medium. Fe (III) subsequently reduces to Fe (II) which is coupled with potassium ferricyanide to form Prussian blue. The reaction is followed spectrophotometrically by measuring the increase in absorbance at λmax 725 nm. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1–20 μg mL-1 for each method. The correlation coefficient was 0.9978 and 0.9993, and LOD was found to be 0.91 and 0.09 μg mL-1 for rate data and fixed time methods, respectively. The proposed method has been successfully applied to the determination of FA in formulations with no interference from the excipients. Statical comparison of the results shows that there is no significant difference between the proposed and pharmacopoeial methods

scholarly journals The Development of a New Kinetic Spectrophotometric Method for the Determination of Vanadium(V) Based on its Catalytic Effect on the Oxidation of Malachite Green Oxalate by Bromate in Acidic and Micellar Medium

2010 ◽  
Vol 7 (4) ◽  
pp. 1612-1620 ◽  
Author(s):  
M. Keyvanfard ◽  
N. Abedi
Keyword(s):  
Malachite Green ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Micellar Medium ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Malachite Green Oxalate

A new, simple, sensitive and selective kinetic spectrophotometric method was developed for the determination of ultra trace amounts of vanadium(V). The method is based on the catalytic effect of vanadium(V) on the oxidation of malachite green oxalate (MG) by bromate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of malachite green oxalate (MG) at 625 nm with a fixed-time method. The decrease in the absorbance of MG is proportional to the concentration of vanadium(V) in the range of 1-100 ng/mL with a fixed time of 0.5-2 min from the initiation of the reaction. The limit of detection is 0.71 ng/mL of vanadium(V). The relative standard deviation for the determination of 5, 30, 50 ng/mL of vanadium(V) was2.5% 2.6%, 2.4% and respectively. The method was applied to the determination of vanadium(V) in water samples.

Kinetic Spectrophotometric Determination of Ruthenium by its Catalytic Effect on the Reduction of Spadns with Sodium Hypophosphite in Micellar Media

2012 ◽  
Vol 204-208 ◽  
pp. 4067-4070 ◽  
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Sodium Hypophosphite ◽  
Micellar Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A simple kinetic spectrophotometric method was developed for the determination of trace amounts of Ru (III). The method is based on the reduction of spadns by sodium hypophosphite (NaH2PO2) in micellar media. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of spadns at 515 nm with a fixed-time method. The decrease in the absorbance of spadns is proportional to the concentration of Ru (III) in the range 0.40–10.0 μg/L with a fixed time of 2.5–7.0 min from the initiation of the reaction. The limit of detection is 0.12 μg/L Ru (III). The relative standard deviation for the determination of 0.10 and 0.20 μg/25mL Ru (III) was 2.3 % and 2.0 %, respectively. The method was applied to the determination of Ru (III) in some ores and metallurgy products.

Kinetic Spectrophotometric Method for the Determination of Selenium (IV) by its Catalytic Effect on the Reduction of Arsenazo III with Sodium Hypophosphite in Micellar Media

2012 ◽  
Vol 554-556 ◽  
pp. 926-933
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Fixed Time ◽  
Sodium Hypophosphite ◽  
Micellar Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric

A simple and sensitive kinetic spectrophotometric method for the determination of trace selenium (IV) is described, based on its catalytic effect on the reduction arsenazo III (AsA III) with sodium hypophosphite (NaH2PO2) in a solution of 0.02 mol/L sulfuric acid and in the presence of cationic micellar media. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of AsA III at 550 nm with a fixed-time method. The decrease in the absorbance of AsA III is proportional to the concentration of Se(IV) in the range 0.16–1.0 µg/L after a fixed time of 4–10 min from the initiation of the reaction. The limit of detection is 0.049 µg/L Se(IV). The influence of th e factors such as acidity, concentration of reactants, type and concentration of surfactants, reactive time, temperature and co-existing ions on the reaction is discussed. The optimum reaction conditions of reaction are established and some kinetic parameters are determined; the apparent activation energy of catalytic reaction is 59.51 kJ/mol. The relative standard deviation for eleven replicate determination of 0.02, and 0.01µg/25mL Se(IV) was 2.0 % and 2.4 %, respectively. Combined with sulphydryl dextrane gel (SDG) separation and enriching, the method has been successfully applied to the determination of Se (IV) in foodstuff and human hair samples with the relative standard deviation of 2.1 %–5.8 % and the recovery of 97.0 %–103.3 %, the results are in good agreement with those provided by ICP-AES method.

scholarly journals Kinetic- spectrophotometric Method for the Determination of Naringenin in Pure and Supplements Formulations

2019 ◽  
Vol 16 (3) ◽  
pp. 0595
Author(s):  
ALmashhadani Et al.
Keyword(s):  
Prussian Blue ◽  
Correlation Coefficient ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Fixed Time ◽  
Calibration Graph ◽  
Maximum Absorbance ◽  
Kinetic Spectrophotometric

          Simple, cheap, sensitive, and accurate kinetic- spectrophotometric method has been developed for the determination of naringenin in pure and supplements formulations. The method is based on the formation of Prussian blue. The product dye exhibits a maximum absorbance at 707 nm. The calibration graph of naringenin was linear over the range 0.3 to 10 µg ml-1 for the fixed time method (at 15 min) with a correlation coefficient (r) and percentage linearity (r2%) were of 0.9995 and 99.90 %, respectively, while the limit of detection LOD was 0.041 µg ml-1. The method was successfully applied for the determination of naringenin in supplements with satisfactory results.

scholarly journals Kinetic Spectrophotometric Method for the Determination of Ranitidine and Nizatidine in Pharmaceuticals

2002 ◽  
Vol 85 (6) ◽  
pp. 1316-1323 ◽  
Author(s):  
Mohamed I Walash ◽  
Fathalla Belal ◽  
Fawzia Ibrahim ◽  
Mohamed Hefnawy ◽  
Manal Eid
Keyword(s):  
Spectrophotometric Method ◽  
Reaction Pathway ◽  
Kinetic Method ◽  
Fixed Time ◽  
Borate Buffer ◽  
The Other ◽  
Average Recovery ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

Abstract An accurate and simple kinetic method is described for the determination of ranitidine and nizatidine in pure form and in pharmaceuticals. The method is based on the reaction of the compounds with 7-chloro-4-nitrobenz-2-oxa-1,3-diazole in pH 7.4 borate buffer at 60°C for a fixed time of 25 min for both compounds. The absorbance of the reaction product is measured at 495 nm for ranitidine and nizatidine. Calibration graphs were linear over the concentration range of 2–20 μg/mL, with limits of detection of 0.13 (3.7 × 10−7M) and 0.25 μg/mL (7.5 × 10−7M) for ranitidine and nizatidine, respectively. The proposed method was applied successfully to the determination of ranitidine in tablets and ampoules with average recoveries of 100.26 ± 0.69 and 100.29 ± 0.59%, respectively, and to the determination of nizatidine in capsules with an average recovery of 104.26 ± 0.44%. The results obtained are in good agreement with those obtained by the other methods used for comparison. A proposal of the reaction pathway is also presented.

scholarly journals A Novel Indicator Reaction for the Catalytic Determination of V(V) at ppb Levels by the Kinetic Spectrophotometric Method

2018 ◽  
Vol 39 (4) ◽  
pp. 49
Author(s):  
Halil İbrahim Ulusoy ◽  
Ramazan Gürkan
Keyword(s):  
Catalytic Effect ◽  
Tap Water ◽  
Kinetic Method ◽  
Fixed Time ◽  
Entire Concentration Range ◽  
Catalytic Determination ◽  
Certified Value ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

A novel sensitive and relatively selective kinetic method is presented for the determination of V(V), based on its catalytic effect on the oxidation reaction of Ponceau Xylydine by potassium bromate in presence of 5-sulfosalicylic acid (SSA) as activator. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of Ponceau Xylydine at 640 nm between 0.5 to 7 min (the fixed time method) in H3PO4 medium at 25oC. The effect of various parameters such as concentrations of H3PO4, SSA, bromate and Ponceau Xylydine, temperature and ionic strength on the rate of net reaction were studied. The method is free from most interferences, especially from large amounts of V(IV). The decrease in absorbance is proportional to the concentration of V(V) over the entire concentration range tested (1–15 ng mL−1) with a detection limit of 0.46 ng mL–1 (according to statistical 3Sblank/k criterion) and a coefficient of variation (CV) of 1.8% (for ten replicate measurement at 95% confidence level).The proposed method suffers few interferences such as Cr(VI) and Hg(II) ions. The method was successfully applied to the determination of V(V) in tap water, drinking water, bottled mineralwater samples and a certified standard reference material such as SRM-1640 with satisfactory results. The vanadium contents of water samples were also determined by FAAS for a comparison.The recovery of spiked vanadium(V) was found to be quantitative and the reproducibility was satisfactory. It was observed that the results of the SRM 1640 were in good agreement with the certified value.

scholarly journals A New Inhibition Kinetic Spectrophotometric Method for the Determination of Resorcinol

2010 ◽  
Vol 7 (3) ◽  
pp. 727-732
Author(s):  
Mohsen Keyvanfard
Keyword(s):  
Spectrophotometric Method ◽  
Fixed Time ◽  
Inhibitory Effect ◽  
Cresyl Violet ◽  
Relative Standard ◽  
Fast Kinetic ◽  
Kinetic Spectrophotometric ◽  
Replicate Measurements ◽  
Catalyzed Oxidation

A new, simple, inexpensive and fast kinetic spectrophotometric method was developed for the determination of trace amounts of resorcinol over the range of 0.02-0.80 μg/mL. The method is based on the inhibitory effect of resorcinol on the formaldehyde catalyzed oxidation reaction of of cresyl violet by bromate in acidic media is reported. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of cresyl violet at 596 nm with a fixed-time 0.5–2.5 min from initiation of the reaction.The detection limit is 0.017 μg/mL and relative standard deviation of 0.1 and 0.5 μg/mL resorcinol for six replicate measurements was 2.6 and 2.9 %, respectively. The method was applied to the determination of resorcinol in water samples.

scholarly journals Kinetic Spectrophotometric Method for Determination of Vanadium in Syrian Oil Using 1,5-Diphenylcarbazide Reagent

2016 ◽  
Vol 67 ◽  
pp. 42-49 ◽  
Author(s):  
Issa Moustafa ◽  
Mouhammed Khateeb ◽  
Obaida Alhamed
Keyword(s):  
Crude Oil ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Statistical Treatment ◽  
Fixed Time ◽  
Buffer Solution ◽  
Colored Complex ◽  
Heavy Product ◽  
Kinetic Spectrophotometric

New, sensitive, accurate and inexpensive kinetic spectrophotometric method was developed and validated for the determination of V(V) in crude oil and its heavy product. The method is based on the formation of colored complex between V(V) and 1, 5-diphenylcarbazide (DPCI). The method involves the reaction of V(V) with DPCI in presence of buffer solution of pH 6.8 to form colored complex with λmax at 530 nm. The fixed time method (2000 Sec) was adopted for constructing the calibration curve. The linearity range was found to be (2-12) mg/L. The correlation coefficient was 0.9999 and the limit of detection was found to be 0.349 mg/L. The method is feasible with the calibration equations obtained, which makes this method more applicable. Statistical treatment of the experimental results indicates that the method is precise, selective and accurate. The method was successfully applied for determination of V(V) in Syrian crude oil and its heavy product.

Kinetic Spectrophotometric Method for the Determination of Trace Ruthenium(III) by its Catalytic Effect on the Oxidation of Dibromo Caboxy Arsenazo with Bromate in Cationic Micellar Media

2012 ◽  
Vol 602-604 ◽  
pp. 1289-1293 ◽  
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Catalytic Effect ◽  
Fixed Time ◽  
Micellar Medium ◽  
Micellar Media ◽  
Relative Standard ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

A spectrophotometric method was developed for the determination of trace Ru (III) is described, based on its catalytic effect of Ru (III) on the oxidation of dibromo caboxy arsenazo (DBCAA) by bromate in acidic and micellar medium at 100 °C. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of the catalytic reaction of DBCAA at 530 nm with a fixed-time method. The calibration curve for the recommended method was linear in the concentration range over 0.037–1.0 µg/L and the detection limit of the method for Ru (III) was 0.011 µg/L. The method was applied to the determination of Ru (III) in some ores and metallurgy products. The results are in good agreement with the recommend values with the relative standard deviation of 2.6 %–3.8 % and the recovery of 97.2 %–104.3 %.

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