scholarly journals A Sensitive Spectrophotometric Determination of Ritodrine, Pentazocine, Isoxsuprine Hydrochlorides and Amoxicillin in Pure and Pharmaceutical Samples

2008 ◽  
Vol 5 (1) ◽  
pp. 100-106 ◽  
Author(s):  
H. D. Revanasiddappa ◽  
M. A. Veena
Keyword(s):  
Acid Medium ◽  
The United States ◽  
Molar Absorptivity ◽  
United States Pharmacopoeia ◽  
Hydrochloric Acid Medium ◽  
Subsequent Determination ◽  
Highly Sensitive ◽  
Coloured Complex ◽  
Chloramine T

A simple, accurate and highly sensitive spectrophotometric method for the determination of ritodrine hydrochloride (RTH), pentazocine hydrochloride (PZH), isoxsuprine hydrochloride (ISH) and amoxicillin (AMX) is described. The method is based on the oxidation of the studied drugs by a known excess of chloramine – T (CAT) in hydrochloric acid medium and subsequent determination of the unreacted oxidant by reacting it with iodide in the same acid medium liberates iodine, which subsequently react with starch to form a stable starch-iodine complex. The reacted oxidant corresponds to the drug content. The coloured complex exhibits a maximum absorption at 590 nm. The apparent molar absorptivity values and Sandell’s sensitivity values are in the range 6.96x104- 1.43x105L mol–1cm–1and 2.45-4.30 ng cm–2, respectively. The method was successfully applied to the studied drugs in their dosage forms. The results are reproducible within ±1% and compare favorably with those of official methods of British Pharmacopoeia and the United States Pharmacopoeia.

scholarly journals Sensitive Spectrophotometric Methods for the Determination of Ascorbic Acid

2008 ◽  
Vol 5 (1) ◽  
pp. 10-15 ◽  
Author(s):  
H. D. Revanasiddappa ◽  
M. A. Veena
Keyword(s):  
Ascorbic Acid ◽  
Acid Medium ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Maximum Absorbance ◽  
Hydrochloric Acid Medium ◽  
Subsequent Determination ◽  
Sulphuric Acid Medium

Two simple and sensitive spectrophotometric methods (A and B) have been described for the determination of ascorbic acid. Method A is based on the oxidation of ascorbic acid (AA) by known excess of Se(IV) in hydrochloric acid medium and subsequent determination of unreacted Se(IV) by reacting it with iodide in the same acid medium to liberate iodine, which react with starch to form a stable blue coloured iodine-starch complex, which shows maximum absorbance at 590 nm. Method B is based on the oxidation of ascorbic acid (AA) by known excess of Cr(VI) in sulphuric acid medium and the determination of unreacted Cr(VI) with diphenyl carbazide (DPC) under the same acidic medium to produce a stable red-violet coloured species, which shows a maximum absorbance at 550 nm. The reacted oxidants (in methods A and B) correspond to the AA content. The apparent molar absorptivity values are found to be 1.627×104and 1.641×104L mol-1cm-1for methods A and B, respectively. The proposed methods are simple, sensitive and suitable for the routine analysis of AA in pharmaceutical formulations and in real samples.

scholarly journals Indirect spectrophotometric determination of gentamicin and vancomycin antibiotics based on their oxidation by potassium permanganate

2006 ◽  
Vol 4 (4) ◽  
pp. 708-722 ◽  
Author(s):  
Akram El-Didamony ◽  
Alaa Amin ◽  
Ahmed Ghoneim ◽  
Ayman Telebany
Keyword(s):  
Acid Medium ◽  
Potassium Permanganate ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Reaction Conditions ◽  
Subsequent Determination ◽  
Optimum Reaction ◽  
Acid Orange Ii ◽  
Sulphuric Acid Medium

AbstractFour simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 µg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 µg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.

scholarly journals Sensitive spectrophotometric methods for determination of some organophosphorus pesticides in vegetable samples

2010 ◽  
Vol 16 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Ayman Gouda ◽  
Alaa Amin ◽  
Ragaa El-Sheikh ◽  
Magda Akl
Keyword(s):  
Acid Medium ◽  
Organophosphorus Pesticides ◽  
Molar Absorptivity ◽  
Accurate Analysis ◽  
Spectrophotometric Methods ◽  
Vegetable Samples ◽  
Hydrochloric Acid Medium ◽  
Red Color ◽  
Chromotrope 2R

Three rapid, simple, reproducible and sensitive spectrophotometric methods (A, B and C) are described for the determination of two organophosphorus pesticides, (malathion and dimethoate) in formulations and vegetable samples. The methods A and B involve the addition of an excess of Ce4+ into sulphuric acid medium and the determination of the unreacted oxidant by decreasing the red color of chromotrope 2R (C2R) at a suitable ?max = 528 nm for method A, or a decrease in the orange pink color of rhodamine 6G (Rh6G) at a suitable ?max = 525 nm. The method C is based on the oxidation of malathion or dimethoate with the slight excess of N-bromosuccinimide (NBS) and the determination of unreacted oxidant by reacting it with amaranth dye (AM) in hydrochloric acid medium at a suitable ?max = 520 nm. A regression analysis of Beer-Lambert plots showed a good correlation in the concentration range of 0.1-4.2 ?g mL?1. The apparent molar absorptivity, Sandell sensitivity, the detection and quantification limits were calculated. For more accurate analysis, Ringbom optimum concentration ranges are 0.25-4.0 ?g mL?1. The developed methods were successfully applied to the determination of malathion, and dimethoate in their formulations and environmental vegetable samples.

Extraction and spectrophotometric determination of molybdenum(VI) with N-phenylbenzohydroxamic acid and phenylfluorone

1987 ◽  
Vol 65 (5) ◽  
pp. 1124-1127 ◽  
Author(s):  
H. Dasaratha Gunawardhana ◽  
S. Amarasiri Fernando
Keyword(s):  
Hydrochloric Acid ◽  
Steel Sample ◽  
Chloroform Extract ◽  
Molar Absorptivity ◽  
Hydrochloric Acid Medium ◽  
Coloured Complex ◽  
Method Of Continuous Variation ◽  
Job's Method ◽  
Standard Steel

N-Phenylbenzohydroxamic acid reacts with molybdenum(VI) in 3.5–6.0 M hydrochloric acid to give a complex that is extractable into chloroform. The chloroform extract of the molybdenum complex, on second extraction from a dilute hydrochloric acid medium (0.2–0.3 M) in the presence of phenylfluorone and ethanol, forms an intensely coloured complex possessing an absorption maximum at 518 nm. Job's method of continuous variation reveals that the complex is Mo(VI)—2NPBHA—PF. The molar absorptivity under optimum conditions is 7.4 × 104 cm3 mol−1 cm−1. The system obeys Beer's law up to 0.6 ppm of molybdenum(VI). Considerable amounts of many cations and anions can be tolerated. The interference from vanadium(IV) and vanadium(V) can be eliminated by the addition of sodium metabisulphite, whereas the interference from titanium(IV) is mitigated by oxalate ions. The method has been successfully applied for the determination of molybdenum in a standard steel sample.

scholarly journals Solvent Extraction And Spectrophotomteric Determination Of Cu(Ii) With Dicyclohexyl - 18- Crown-6

2013 ◽  
Vol 10 (3) ◽  
pp. 997-1004
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solution ◽  
Solvent Extraction ◽  
Correlation Coefficient ◽  
Extraction Efficiency ◽  
Molar Absorptivity ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Coloured Complex

Liquid-Liquid Extraction of Cu(II) ion in aqueous solution by dicyclohexyl-18-crown-6 as extractant in dichloroethane was studied .The extraction efficiency was investigated by a spectrophometric method. The reagent form a coloured complex which has been a quantitatively extracted at pH 6.3. The method obeys Beer`s law over range from (2.5-22.5) ppm with the correlation coefficient of 0.9989. The molar absorptivity the stoichiometry of extracted complex is found to be 1:2. the proposed method is very sensitive and selective.

scholarly journals Spectrophotometric determination of metoclopramide hydrochloride in pharmaceutical tablets, by diazotization-coupling method with 1-naphthol as the coupling agent

2010 ◽  
Vol 7 (1) ◽  
pp. 704-712
Author(s):  
Baghdad Science Journal
Keyword(s):  
Detection Limit ◽  
Azo Dye ◽  
Diazonium Salt ◽  
Molar Absorptivity ◽  
British Pharmacopoeia ◽  
Pharmaceutical Tablets ◽  
Hydrochloric Acid Medium ◽  
Metoclopramide Hydrochloride ◽  
Sensitive Spectrophotometric Method

Simple, rapid and sensitive spectrophotometric method was proposed for the analysis of metoclopramide hydrochloride (MPH) in pure form as well as in pharmaceutical tablets. The method is based on the diazotization reaction of MPH with sodium nitrite in hydrochloric acid medium to form diazonium salt, which is coupled with 1-naphthol in sodium hydroxide medium to form azo dye, showing absorption maxima at 550 nm. Beer’s law is obeyed in the concentration range of 0.4 – 18 µg mL-1 of MPH with detection limit 0.5448 µg mL-1. The molar absorptivity and Sandell’s sensitivity are 3.4969 × 104 L mol-1 cm-1 and 0.0101 µg cm-2, respectively. The method was successfully applied to the determination of MPH in pharmaceutical tablets without any interference from common excipients used as additives in tablets. The results agree favorably with the official British Pharmacopoeia method.

scholarly journals Spectrophotometric determination of phosphorus in coal and coal ash using bismuth-phosphomobybdate complex

2003 ◽  
Vol 68 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Randjel Mihajlovic ◽  
Natasa Ignjatovic ◽  
Marija Todorovic ◽  
Ivanka Holclajtner-Antunovic ◽  
Vesna Kaljevic
Keyword(s):  
Aqueous Solution ◽  
Ascorbic Acid ◽  
Acid Medium ◽  
Spectrophotometric Method ◽  
Methyl Ketone ◽  
Coal Ash ◽  
Molar Absorptivity ◽  
Stable Complex ◽  
Tolerance Limits

A modified spectrophotometric method using the bismuth phosphomolybdate complex for the determination of phosphorus in coal and coal ash is suggested. Bismuth together with phosphate and molybdate forms a very stable complex in acid medium which turns blue ("molibdenum blue") by reduction with ascorbic acid. The apparent molar absorptivity of PBiMo is 1.66x104 dm3 mol-1cm-1 at 720 nm and 2.10x104 dm3 mol-1cm-1 at 670 nm isobutyl methyl ketone (MIBK). Interference caused by the ions present are within the tolerance limits (?2 %). Beer?s law is obeyed in the for concentration range to 0.6 ?g/mL (aqueous solution) and to 1.2 ?g/mL P (MIBK). The sensitivity of the proposed method is 0.0078 ?g/mL (aqueous solution) and 0.0066 ?g/mL (MIBK).

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