scholarly journals The Use of a Polyphenoloxidase Biosensor Obtained from the Fruit of Jurubeba (Solanum paniculatum L.) in the Determination of Paracetamol and Other Phenolic Drugs

Biosensors ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 36 ◽  
Author(s):  
Rafael Antunes ◽  
Luane Garcia ◽  
Vernon Somerset ◽  
Eric Gil ◽  
Flavio Lopes
Keyword(s):  
Phenolic Drugs

scholarly journals Determination of Methyldopa and Paracetamol in Pharmaceutical Samples by a Low Cost Genipa americana L. Polyphenol Oxidase Based Biosensor

2019 ◽  
Vol 9 (3) ◽  
pp. 416-422
Author(s):  
Rafael Souza Antunes ◽  
Douglas Vieira Thomaz ◽  
Luane Ferreira Garcia ◽  
Eric de Souza Gil ◽  
Vernon Sydwill Sommerset ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Low Cost ◽  
Differential Pulse ◽  
Pharmaceutical Samples ◽  
Polyphenol Oxidases ◽  
Voltammetric Techniques ◽  
Relative Standard ◽  
Pulse Voltammetry ◽  
Phenolic Drugs

Purpose: Jenipapo fruit (Genipa americana L) is a natural source of polyphenol oxidases (PPOs) whose potential in pharmaceutical analysis is noteworthy. Henceforth, this work reports the electrochemical study of a low-cost PPO-based biosensor produced from the crude extract of Jenipapo fruits and accounts a practical approach to employ this biosensor in the determination of methyldopa and paracetamol in pharmaceutical samples. Methods: In order to investigate the electrochemical properties of the biosensor, theoretical and practical approaches were employed, and both samples and the biosensor were analyzed through electrochemical impedance spectroscopy (EIS) and voltammetric techniques, namely: differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Results: showcased that the biosensor presented good analytical features, as well as low detection limits (8 μmol L-1 for methyldopa and 5 μmol L-1 for paracetamol). The relative standard deviation was less than 5% mid-assay. Conclusion: The use of this biosensor is a reliable, low cost and useful alternative in the pharmaceutic determination of phenolic drugs (e.g. methyldopa and paracetamol).

scholarly journals Spectrophotometric Method for the Determination of Drugs Containing Phenol Group by Using 2, 4- Dinitrophenylhydrazine

2010 ◽  
Vol 7 (2) ◽  
pp. 395-402
Author(s):  
Padmarajaiah Nagaraja ◽  
Ashwinee Kumar Shrestha
Keyword(s):  
Standard Deviation ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Dosage Forms ◽  
Limit Of Quantification ◽  
Pharmaceutical Dosage Forms ◽  
Accuracy And Precision ◽  
Relative Standard ◽  
Phenolic Drugs

A spectrophotometric method has been proposed for the determination of four phenolic drugs; salbutamol, ritodrine, amoxicillin and isoxsuprine. The method is based on the oxidation of 2, 4- dinitrophenyl-hydrazine and coupling of the oxidized product with drugs to give intensely colored chromogen. Under the proposed optimum condition, beer’s law was obeyed in the concentration range of 2.5-17, 2-29, 4-33 and 5-30 μg/mL for salbutamol, ritodrine, amoxicillin and isoxsuprine respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 0.2, 0.83, 0.09, 0.84 μg/mL and 0.66, 2.79, 0.3 and 2.81 μg/mL in the same order. No interference was observed from common pharmaceutical adjuvants. The ringbom plots and low relative standard deviation assert the applicability of this method. The suggested method was further applied for the determinations of drugs in commercial pharmaceutical dosage forms, which was compared statistically with reference methods by means oft- test andF- test and were found not to differ significantly at 95% confidence level. The procedure is characterized by its simplicity with accuracy and precision.

scholarly journals Flow-Injection Spectrophotometric Determination of Phenolic Drugs and Carbamate Pesticides by Coupling with Diazotized 2,4,6-Trimethylaniline

1999 ◽  
Vol 82 (4) ◽  
pp. 937-947 ◽  
Author(s):  
Lluis Alvarez-Rodriguez ◽  
Esteve-Romero Josep ◽  
Imma Escrig-Tena ◽  
M Celia Garcia Alvarez-Coque
Keyword(s):  
Flow Injection ◽  
Sodium Dodecyl ◽  
Coupling Reaction ◽  
The Self ◽  
Micellar Media ◽  
Carrier Stream ◽  
Diazonium Ion ◽  
Phenolic Drugs ◽  
Aqueous Micellar Medium

Abstract A flow-injection (FI) spectrophotometric system is proposed for the determination of phenols and carbamates. In the FI manifolds, the solutions of phenols or carbamates (the latter after hydrolysis with NaOH) were injected into a diazonium ion carrier stream at pH 9.5 (buffered with tetrahydroborate), which was formed by mixing 2,4,6-trimethylaniline (TMA) with nitrate in a sodium dodecyl sulfate aqueous micellar medium. Absorbance was measured at 550 nm. The system combines the advantages derived from the use of TMA for the coupling of phenols in basic micellar media, because of the inhibition of the self-coupling reaction of the reagent, with the precision and speed of the FI procedures. Other diazotized reagents produced excessive blank signals. The procedures were successfully applied to the determination of phenolic drugs (epinephrine, acetaminophen, and guaiacol) in pharmaceuticals and carbamates (bendiocarb, benfuracarb, carbaryl, carbofuran, methiocarb, promecarb, and propoxur) in pesticide products and water samples.

Sodium Cobaltinitrite as a Reagent for Determining Some Phenolic Drugs

1978 ◽  
Vol 61 (5) ◽  
pp. 1113-1117
Author(s):  
Abdel-Aziz M Wahbi ◽  
Hassan Abdine ◽  
Mohamed Korany ◽  
Mohamed H Abdel-Hay
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Coefficient Of Variation ◽  
Maximum Absorption ◽  
Aqueous Acetic Acid ◽  
Salbutamol Sulfate ◽  
Tablet Form ◽  
Yellow Color ◽  
Phenolic Drugs

Abstract Dichlorophen, oxyphenbutazone, phenazone, methyldopa, isoprenaline sulfate, and salbutamol sulfate are reacted with sodium cobaltinitrite in aqueous acetic acid. The yellow color is measured at 365, 320, 320, 330, 425, and 325 nm in aqueous acetic acid, respectively, and at 445, 380, 375, 345, 325, and 412 nm in sodium hydroxide, respectively. The reaction product is extractable with CHC13, with a maximum absorption at 370 nm for dichlorophen, 355 nm for phenazone, and 325 nm for oxyphenbutazone. The method is applied to the determination of these drugs in tablet form. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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