Second Derivative Spectrophotometric Determination of Acetaminophen and Phenacetin in Presence of Their Degradation Products

1986 ◽  
Vol 69 (4) ◽  
pp. 608-611
Author(s):  
Mohamed A Korany ◽  
Mona Bedair ◽  
Hoda Mahgoub ◽  
Mahmoud A Elsayed
Keyword(s):  
Spectrophotometric Determination ◽  
Degradation Products ◽  
Spectral Response ◽  
Accurate Method ◽  
Second Derivative ◽  
The Mean ◽  
The Stability

Abstract A rapid and accurate method for determining acetaminophen and phenacetin in presence of their degradation products is presented. Solutions of these drugs in 0.1N HC1 were analyzed by measuring their second derivative spectral response at 295 nm where the degradation products do not interfere. The mean percent recoveries for mixtures of acetaminophen and/or phenacetin with the corresponding degradation products were 100.2 ± 0.6 and 100.6 ± 1.1, respectively. The method can be used for assessing the stability of the 2 drugs. The proposed method is also applied to the determination of acetaminophen in tablets and syrups.

Complexation equilibria between gallium(III) and 4-(4'-methyl-2'-thiazolylazo)-2-methylresorcinol. Derivative spectrophotometric determination of gallium in biological samples

1990 ◽  
Vol 55 (6) ◽  
pp. 1500-1507 ◽  
Author(s):  
Ana I. Jiménez ◽  
Francisco Jiménez ◽  
Juan P. Pérez ◽  
Juan J. Arias
Keyword(s):  
Blood Serum ◽  
Numerical Method ◽  
Stability Constants ◽  
Spectrophotometric Determination ◽  
Human Urine ◽  
Biological Samples ◽  
Second Derivative ◽  
Serum Samples ◽  
The Stability

The reaction of Ga(III) with 4-(4'-methyl-2'-thiazolylazo)-2-methylresorcinol (H2L) at I = 0.25 mol l-1, (NaNO3) was investigated spectrophotometrically. Numerical method was used to evaluate the stability constants of the complexes formed GaH2L2 (log β122 = 37.03±0.09); GaHL (log β111 = 19.08±0.06); GaL (log β101 = 13.65±0.16). A method is developed for the determination of gallium using first and second derivative spectrophotometry and the effect of interferences has been evaluated. The method has been applied to the determination of gallium in human urine and blood serum samples.

Simultaneous Second Derivative Spectrophotometric Determination of Manganese and Copper

1992 ◽  
Vol 25 (8) ◽  
pp. 1581-1593 ◽  
Author(s):  
A. R. Fernández-Alba ◽  
J. L. Martínez-Vidal ◽  
P. Aguilera ◽  
F. Freniche ◽  
A. Agüera
Keyword(s):  
Spectrophotometric Determination ◽  
Second Derivative

scholarly journals Rapid Spectrophotometric Determination of Phenoxazine

2010 ◽  
Vol 7 (2) ◽  
pp. 1001-1005
Author(s):  
Baghdad Science Journal
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Acidic Medium ◽  
Absorption Maximum ◽  
Aqueous Samples ◽  
Economic Method ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Stability

A rapid high sensitive and inexpensive economic method has been developed for the Determination of phenoxazine by using molecular spectrophotometry. The method is based on the oxidation of phenoxazine by potassium (meta)periodate in acidic medium. The oxidation conditions were selected to enhance the sensitivity and the stability of the pink colored species which shows an absorption maximum at 530 nm. The Beer’s law was obeyed for phenoxazine concentration range from 1 to 6 µg mL-1 with 0.003 µg mL-1 detection limit and provided variation coefficients between 0.4 to 1.7 %. This method was successfully applied for the determination of phenoxazine in aqueous samples

Fluorometric and Spectrophotometric Determination of Pirbuterol Hydrochloride in Authentic and Dosage Forms

1985 ◽  
Vol 68 (6) ◽  
pp. 1222-1225
Author(s):  
Mohamed E Mohamed ◽  
Hassan Y Aboul-Enein
Keyword(s):  
Potentiometric Titration ◽  
Alkaline Medium ◽  
Spectrophotometric Determination ◽  
Fluorescence Intensity ◽  
Perchloric Acid ◽  
Authentic Sample ◽  
Dosage Forms ◽  
Fluorometric Method ◽  
The Mean

Abstract Pirbuterol hydrochloride has been assayed in alkaline medium by using a fluorometric method to measure fluorescence intensity at 372 nm with excitation at 310 nm and by the ▵A method at 242 nm.The linearity ranges are 0.5-4 μg/mL and 10-50 μg/mL, respectively. An authentic pirbuterol HC1 sample was analyzed by nonaqueous potentiometric titration using 0.1N perchloric acid, and the results were compared with those for fluorometric and AA methods. The mean percent recoveries for the authentic sample were 98.72 ± 1.13 and 99.24 ± 0.85, respectively. When applied to commercial capsules containing 10 mg and 15 mg each, the fluorometric method gave mean percent recoveries of 101.11 ± 1.05 and 98.12 ± 0.93; the ▵A method gave mean percent recoveries of 100.57 ± 0.83 and 97.80 ± 0.75, respectively.

scholarly journals Solid-Phase Extraction and Gas Chromatography with Mass Spectrometric Determination of Capsaicin and Some of Its Analogues from Chili Peppers (Capsicum spp.)

1999 ◽  
Vol 82 (6) ◽  
pp. 1399-1405 ◽  
Author(s):  
Philemon Manirakiza ◽  
Adrian Covaci ◽  
Paul Schepens
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Solid Phase ◽  
Accurate Method ◽  
Mass Spectrometric ◽  
Phase Extraction ◽  
Capsicum Spp ◽  
The Mean ◽  
Chili Peppers

Abstract A rapid and accurate method has been developed for the quantitative determination of capsaicin and its most important analogues, dihydrocapsaicin and nordihydrocapsaicin in chili peppers. These components were extracted with methylene chlo ride and separated from interfering substances with activated charcoal. Further cleanup on Florisil cartridges and elution with ethyl acetate were performed before gas chromatographic with mass spectrometric quantitation. The concentrations found were 440 ± 64 μg/g capsaicin, 81 ± 10 μg/g dihydrocapsaicin, and 11 ± 2 μg/g nordihydrocapsaicin. The mean recovery values for triplicate analysis were between 85-94%.

Stability-Indicating Liquid Chromatographic Procedure for Determination of Allantoin in Cosmetic Lotion

1988 ◽  
Vol 71 (2) ◽  
pp. 290-294
Author(s):  
Ramesh J Trivedi
Keyword(s):  
Degradation Products ◽  
Glyoxylic Acid ◽  
Uv Detector ◽  
Stability Indicating ◽  
Assay Procedure ◽  
Relative Standard ◽  
The Stability ◽  
Chromatographic Parameters ◽  
Liquid Chromatographic

Abstract A sensitive, specific liquid chromatographic (LC) procedure was developed for determination of allantoin [(2,5-dioxo-4--imidaazolidinyl) urea or 5-ureidohydantion] in cosmetic lotion. A reverse-phase, ionsuppression mechanism separated allantoin from interfering constituents of the sample matrix, and the compound was determined with a UV detector at 240 nm with a sensitivity limit of ((.20 mg/mL. The chromatographic parameters were optimized for retention time, efficiency, and relative response to the analyte. The assay procedure was validated with spiked laboratory-prepared samples at 100 ± 15% levels. An average recovery of 99.4% with a relative standard deviation of 1.5% (n = 7) was obtained. The stability-indicating characteristics of the method were established by recovery study (99.8%) of samples spiked with known degradation products (urea, allantoic acid, and glyoxylic acid).

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