Photocatalytic Discoloration of Methyl Orange and Indigo Carmine on TiO2 (P25) Deposited on Conducting Substrates: Effect of H2O2 and S2O82-

2012 ◽  
Vol 4 (2) ◽  
pp. 45-56 ◽  
Author(s):  
Tomkouani Kodom ◽  
Etsri Amouzou ◽  
Gbandi Djaneye-Bo ◽  
Limam Moctar Bawa
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine

scholarly journals Use of ceric ammonium sulphate and two dyes, methyl orange and indigo carmine, in the determination of lansoprazole in pharmaceuticals

2007 ◽  
Vol 57 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Veeraiah Ramakrishna ◽  
Urdigere Kumar
Keyword(s):  
Methyl Orange ◽  
Ammonium Sulphate ◽  
Indigo Carmine ◽  
Correlation Coefficients ◽  
Standard Addition ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Bulk Drug

Use of ceric ammonium sulphate and two dyes, methyl orange and indigo carmine, in the determination of lansoprazole in pharmaceuticalsTwo spectrophotometric methods are proposed for the assay of lansoprazole (LPZ) in bulk drug and in dosage forms using ceric ammonium sulphate (CAS) and two dyes, methyl orange and indigo carmine, as reagents. The methods involve addition of a known excess of CAS to LPZ in acid medium, followed by determination of residual CAS by reacting with a fixed amount of either methyl orange, measuring the absorbance at 520 nm (method A), or indigo carmine, measuring the absorbance at 610 nm (method B). In both methods, the amount of CAS reacted corresponds to the amount of LPZ and the measured absorbance was found to increase linearly with the concentration of LPZ, which is corroborated by the correlation coefficients of 0.9979 and 0.9954 for methods A and B, respectively. The systems obey Beer's law for 0.5-7.0 μg mL-1and 0.25-3.0 μg mL-1for methods A and B, respectively. The apparent molar absorptivities were calculated to be 3.0 x 104and 4.4 x 104L mol-1cm-1for methods A and B, respectively. The limits of detection (LOD) and quantification (LOQ) were calculated to be 0.08 and 0.25 μg mL-1for method A, and 0.09 and 0.27 μg mLs-1for method B, respectively. The intra-day and inter-day precision and accuracy of the methods were evaluated according to the current ICH guidelines. Both methods were of comparable accuracy (er≤ 2 %). Also, both methods are equally precise as shown by the relative standard deviation values < 1.5%. No interference was observed from common pharmaceutical adjuvants. The accuracy of the methods was further ascertained by performing recovery studies using the standard addition method. The methods were successfully applied to the assay of LPZ in capsule preparations and the results were statistically compared with those of the literature UV-spectrophotometric method by applying Student'st-test andF-test.

scholarly journals New Sensitive Spectrophotometric Methods for the Determination of Raloxifene Hydrochloride in Pharmaceuticals Using Bromate-Bromide,Methyl Orange and Indigo Carmine

2006 ◽  
Vol 3 (4) ◽  
pp. 242-249 ◽  
Author(s):  
K Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine ◽  
Reference Method ◽  
Standard Addition ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Hydrochloric Acid Medium ◽  
Student’S T ◽  
Raloxifene Hydrochloride

Two new sensitive spectrophotometric methods are proposed for the determination of raloxifene hydrochloride (RLX) using bromate-bromide mixture and two dyes, methyl orange and indigocarmine, as reagents. The methods entail the addition of a known excess of bromate-bromide mixture to RLX in hydrochloric acid medium followed by determination of residual bromine by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A) or indigo carmine and measuring the absorbance at 610 nm (Method B). In both methods, the amount of bromine reacted corresponds to the amount of RLX. The absorbance is found to increase linearly with concentration of RLX. Under the optimum conditions, RLX could be assayed in the concentration range 0.1-2.0 and 0.5-6.0 μg mL-1by method A and method B, respectively. The apparent molar absorptivities are calculated to be 1.9×105and 4.5×104L mol-1cm-1for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.003 and 0.011 μg cm-2. The limits of detection and quantification are also reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the assay of RLX in its tablet formulation and the results were compared with those of a reference method by calculating the Student’s t-value and F-value. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by recovery experiments via standard-addition procedure.

scholarly journals Titrimetric and Spectrophotometric Determination of Metaprolol tartrate in Pharmaceuticals Using N-Bromosuccinimide

2007 ◽  
Vol 4 (1) ◽  
pp. 117-127 ◽  
Author(s):  
K. Basavaiah ◽  
B. C. Somashekar
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine ◽  
Reference Method ◽  
Standard Addition ◽  
Reaction Conditions ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Bulk Drug ◽  
Reaction Stoichiometry

One titrimetric and two spectrophotometric methods are presented for the assay of metaprolol tartrate (MPT) in bulk drug and in tablets. The methods employ N-bromosuccinimide (NBS) as the oxidimetric reagent and two dyes, methyl orange and indigo carmine as spectrophotometric reagents. In titrimetry, an acidified solution of MPT is treated with a known excess amount of NBS and after a definite time, the unreacted oxidant is determined by iodometric back titration. Spectrophotometry involves adding a measured excess of NBS to MPT in acid medium followed by determination of residual NBS by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A) or indigo carmine and measuring the absorbance at 610 nm (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of MPT. Reaction conditions have been optimized. Titrimetry allows the determination of 1 - 12 mg of MPT and the calculations are based on a 1: 4 (MPT: NBS) reaction stoichiometry. In spectrophotometry, the measured absorbance is found to increase linearly with the concentration of MPT serving as basis for quantitation. The systems obey Beer’s law for 0.5 - 4.0 μg mL-1and 1.25 - 10.0 μg mL-1for method A and method B, respectively. The apparent absorptivities are calculated to 1.07 × 105be and 4.22 × 104L mol cm-1for method A and method B, respectively. The methods developed were applied to the assay of MPT in commercial tablet formulations, and the results were compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard-addition method.

scholarly journals Bromatomatric assay of gatifloxacin in pharmaceuticals

2008 ◽  
Vol 14 (3) ◽  
pp. 185-190
Author(s):  
Kanakapura Basavaiah ◽  
Urdigere Kumar ◽  
Kalsang Tharpa
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine ◽  
Pharmaceutical Preparations ◽  
Cost Effective ◽  
Thymol Blue ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Hydrochloric Acid Medium ◽  
Ich Guidelines

Three new, simple, and cost-effective visible spectrophotometric methods are proposed for determination of gatifloxacin (GTF) using bromate-bromide mixture, and three dyes, methyl orange, indigocarmine and thymol blue, as reagents. The methods engross the addition of a known excess of bromate-bromide mixture to GTF in hydrochloric acid medium followed by determination of residual bromine by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (method A) or indigo carmine and measuring the absorbance at 610 nm (method B) or thymol blue and measuring the absorbance at 550 nm (method C). In all the methods, the amount of bromine reacted corresponds to the amount of GTF, and the absorbance is found to increase linearly with the concentration of GTF. Under the optimum conditions, GTF could be assayed in the concentration range 0.25-1.5, 0.5-6.0, and 0.5-10 mg/mL by method A, method B and method C, respectively. The apparent molar absorptivities are calculated to be 1.6x105, 4.0x104 and 3.2x104 L mol-1 cm-1 for the method A, method B and method C, respectively, and the corresponding Sandell sensitivity values are 0.0025, 0.010 and 0.012 ?g/cm2. The intra-day and inter-day precision, and the accuracy of the methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the determination of GTF in pharmaceutical preparations without the interference from any of the pharmaceutical adjuvant.

scholarly journals Effect of Time on the Adsorption of Methylene Blue, Methyl Orange and Indigo Carmine onto Activated Carbon

2016 ◽  
Vol 09 (09) ◽  
pp. 55-62 ◽  
Author(s):  
Ocholi O.J ◽  
Gimba C.E ◽  
Ndukwe G.I ◽  
Turoti M ◽  
Abechi S.E ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Methyl Orange ◽  
Indigo Carmine

scholarly journals Titrimetric and spectrophotometric determination of doxycycline hyclate using bromate-bromide, methyl orange and indigo carmine

2010 ◽  
Vol 16 (2) ◽  
pp. 139-148 ◽  
Author(s):  
Jagannathamurthy Ramesh ◽  
Kanakapura Basavaiah ◽  
Ranganath Divya ◽  
Nagaraju Rajendraprasad ◽  
Basavaiah Vinay
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine ◽  
Molar Absorptivity ◽  
Stoichiometric Ratio ◽  
Doxycycline Hyclate ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Bulk Drug

One titrimetric and two indirect spectrophotometric methods are described for the determination of doxycycline hyclate (DCH) in bulk drug and in its formulations. The methods use bromate-bromide, methyl orange and indigo carmine as reagents. In titrimetry (method A), DCH is treated with a known excess of bromate-bromide mixture in acid medium and the residual bromine is back titrated iodometrically after the reaction between DCH and in situ bromine is ensured to be complete. In spectrophotometric methods, the excess of bromine is estimated by treating with a fixed amount of either methyl orange (method B) or indigo carmine (method C) and measuring the change in absorbance either at 520 or 610 nm. Titrimetric method is applicable over 1-8 mg range and the calculations are based on a 1:2 (DCH:bromate) stoichiometric ratio. In spectrophotometry, the calibration graphs were found to be linear over 0.25-1.25 and 1-5 ?g mL-1 for method B and method C, respectively, with corresponding molar absorptivity values of 2.62 ?105 and 6.97 ? 104 L mol-1 cm-1. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of DCH.

scholarly journals Titrimetric and spectrophotometric assay of felodipine in tablets using bromate–bromide, Methyl Orange and Indigo Carmine reagents

2005 ◽  
Vol 70 (7) ◽  
pp. 969-978 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Umakanthappa Chandrashekar ◽  
Nage Gowda
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine ◽  
Reference Method ◽  
Pharmaceutical Formulations ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Bulk Drug ◽  
Reaction Stoichiometry ◽  
Comparison Of The Results

Three new methods based on titrimetric and spectrophotometric techniques are described for the determination of felodipine (FLD) in the bulk drug and in tablets using a bromate?bromide mixture and two dyes, Methyl Orange and Indigo Carmine. In the titrimetric method (method A), the drug solution was treated with a measured excess of the bromate?bromide mixture in acid medium and after the reaction was judged to be complete, the unreacted bromine was determined iodometrically. The two spectrophotometric methods are based on the bromination of the drug with a known excess of the bromate?bromide mixture under acidic conditions followed by the estimation of the surplus bromine by reaction with either Methyl Orange (Method B) or Indigo Carmine (Method C) and measuring the absorbance at 520 nm or 610 nm, respectively. In all the methods, the amount of reacted bromine corresponds to the drug content. The titrimetric procedure is applicable for between 6?15 mg and the reaction stoichiometry was found to be 1:1 (drug: BrO3?). The systems obey Beer?s law between 0.12 ? 0.87 ?gml-1 and 0.5 ? 6.0 ?gml-1 formethods B and C respectively. The limits of detection and quantification are reported for both the spectrophotometric methods. The methods could usefully be applied to routine quality control of pharmaceutical formulations containing FLD. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

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