scholarly journals Validation of a UV Spectrometric Method for the Assay of Tolfenamic Acid in Organic Solvents

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Sofia Ahmed ◽  
Nafeesa Mustaan ◽  
Muhammad Ali Sheraz ◽  
Syeda Ayesha Ahmed un Nabi ◽  
Iqbal Ahmad
Keyword(s):  
Organic Solvents ◽  
Statistical Data ◽  
Tolfenamic Acid ◽  
The Other ◽  
Spectrometric Method ◽  
Solution Stability ◽  
Solvent Interactions ◽  
Stock Solutions ◽  
Better Than

The present study has been carried out to validate a UV spectrometric method for the assay of tolfenamic acid (TA) in organic solvents. TA is insoluble in water; therefore, a total of thirteen commonly used organic solvents have been selected in which the drug is soluble. Fresh stock solutions of TA in each solvent in a concentration of 1 × 10−4 M (2.62 mg%) were prepared for the assay. The method has been validated according to the guideline of International Conference on Harmonization and parameters like linearity, range, accuracy, precision, sensitivity, and robustness have been studied. Although the method was found to be efficient for the determination of TA in all solvents on the basis of statistical data 1-octanol, followed by ethanol and methanol, was found to be comparatively better than the other studied solvents. No change in the stock solution stability of TA has been observed in each solvent for 24 hours stored either at room (25±1°C) or at refrigerated temperature (2–8°C). A shift in the absorption maxima has been observed for TA in various solvents indicating drug-solvent interactions. The studied method is simple, rapid, economical, accurate, and precise for the assay of TA in different organic solvents.

Study on Preparation and Property of Drug Loading of AZM-PCL Nanoparticels

2011 ◽  
Vol 121-126 ◽  
pp. 1764-1768
Author(s):  
Li Li Ruan ◽  
Da Xin Wang ◽  
You Wei Zhang ◽  
Jiong Xin Zhao ◽  
Min Wu Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Size Distribution ◽  
Organic Solvents ◽  
Drug Loading ◽  
Average Diameter ◽  
Preparation Condition ◽  
The Other ◽  
Distribution Index ◽  
Model Drug ◽  
Better Than

This study was to prepare polycaprolactone (PCL) nanoparticles. The biodegradable PCL was used as the carrier, and Azithromycin (AZM) was used as the model drug. AZM-PCL nanoparticles (AZM-PCL-NPS) were prepared by desolvation method. The effect of preparation condition: concentration of PCL, molecular weight of PCL, organic solvents, dosage ratio and so on, were specially noted and compared. A homogeneous size distribution and good dispersion were observed, the average diameter was around 70~400 nm, and the distribution index was 0.036~0.136. The drug loading reached 27.69 %, and the efficiency of encapsulation reached as high as 93.25%. The results were better than the other similar researches, this preparation way was successful.

Effect of the Water Spectrum on the Determination of Dissolved Ammonia, Urea, and Chloride Concentrations by Raman Spectroscopy

1998 ◽  
Vol 52 (2) ◽  
pp. 240-249 ◽  
Author(s):  
Hsiaoling Wang ◽  
Chao Wang ◽  
Charles K. Mann ◽  
Thomas J. Vickers
Keyword(s):  
Least Squares ◽  
Partial Least Squares ◽  
The Other ◽  
Ammonium Salts ◽  
Ammonium Ion ◽  
Water Band ◽  
Chloride Concentrations ◽  
Better Than ◽  
Least Squares Approach

The effect of large, changing concentrations of electrolytes on the behavior of the OH stretching band of water have been investigated with the aim of developing methods for compensating for spectral interferences when solute NH bands are made the basis for mixture analyses. With the use of urea and ammonium salts as analytes, it was found that changing electrolyte concentrations affect the shape of the water band but do not appreciably affect the shapes of either the ammonium ion or urea Raman lines. Chlorides, nitrates, and mixtures of these were used as electrolytes. The identity of the anion had a significant effect on the shape of the OH band. Two methods of compensation were used. One involved factor analyzing the spectra of a set of solutions that contained chlorides and nitrates that are Raman inactive in the vicinity of the OH stretching band. The principal abstract factors were used in place of a water reference for a least-squares mixture analysis. The other method was application of partial least-squares. In addition to urea and ammonium ion, the concentration of KCl and the ionic strength of the system can be determined in the partial least-squares approach with limits of detection better than 0.1 M.

Emission spectrometric method for determination of water in organic solvents

1975 ◽  
Vol 22 (2) ◽  
pp. 146-148
Author(s):  
E. A. Kuchkarev ◽  
E. G. Vlasova ◽  
�. N. Avdeeva ◽  
N. D. Rumyantseva
Keyword(s):  
Organic Solvents ◽  
Spectrometric Method

DETERMINATION OF TOTAL ORGANIC PHOSPHORUS IN SOILS BY EXTRACTION METHODS

1963 ◽  
Vol 43 (1) ◽  
pp. 35-43 ◽  
Author(s):  
J. F. Dormaar ◽  
G. R. Webster
Keyword(s):  
Organic Solvents ◽  
Hydrofluoric Acid ◽  
Organic Phosphorus ◽  
Extraction Methods ◽  
The Other ◽  
Blue Color ◽  
Cent Level ◽  
Analytical Time ◽  
Selection Of

Comparisons were made between the quantities of organic phosphorus extracted from some Alberta soils by the Kaila-Virtanen method (10), an expanded Kaila-Virtanen procedure, and the Mehta et al. method (15). The modifications for the Kaila-Virtanen method were introduced as a result of the present study.One of the main difficulties encountered in the expanded procedure was the selection of organic solvents that would not interfere with the molybdophosphoric blue color reaction. The non-interfering acetone and acetone containing 0.2 M acetyl acetone gave increased extraction of organic phosphorus from the surface and B horizon samples, respectively. Hydrofluoric acid was recommended for B horizon samples.The expanded Kaila-Virtanen procedure extracted significantly more organic phosphorus (at 5 per cent level) than either of the other methods. The expanded Kaila-Virtanen method does not require more analytical time than the original. Furthermore, as a result of a larger number of extractions involved, this expanded procedure should have an advantage over the other two for studying the various forms of organic phosphorus extracted.

scholarly journals Development of a Gas Chromatographic/Mass Spectrometric Method for Determination of Phthalates in Oily Foods

2010 ◽  
Vol 93 (1) ◽  
pp. 315-322 ◽  
Author(s):  
Anna Sannino
Keyword(s):  
Ion Trap ◽  
Mass Spectrometric ◽  
The Other ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Florisil Column ◽  
Dibutyl Sebacate ◽  
Full Scan ◽  
Chromatographic Mass

Abstract A GC/MS method was developed for simultaneous determination of 12 phthalates and four other plasticizersacetyl tributyl citrate, di(2-ethylhexyl) adipate, dibutyl sebacate, di-isononyl cyclohexane 1,2-dicarboxylate (DINCH)in vegetable oil, pesto, and tomato sauce. Samples were extracted with acetonitrile and cleaned on a Florisil column. The final extract was analyzed by GC in combination with ion trap MS. The phthalates and di-isononyl cyclohexane 1,2-dicarboxylate were detected by MS/MS, while the other three plasticizers were monitored in the same GC run using full scan mode. The analytical process was validated in each matrix by the analysis of blank samples. Performance characteristics, such as linearity, LOQ, precision, and recoveries were studied. Studies at fortification levels of 0.25200 mg/kg gave mean recoveries ranging from 71 to 106 and RSD values between 7 and 12 for all compounds. LOQs were 0.0500.10 mg/kg for all the target compounds except di-isononyl phthalate, di-isodecyl phthalate, and DINCH (2.0 mg/kg).

Petrus Montanus as a Phonetician and a Theoretician

1988 ◽  
Vol 15 (1-2) ◽  
pp. 85-108 ◽  
Author(s):  
Jos L. M. Hulsker
Keyword(s):  
Spoken Language ◽  
Precise Determination ◽  
The Other ◽  
Speech Sounds ◽  
Object A ◽  
Complete Survey ◽  
Simon Stevin ◽  
Better Than

Summary Petrus Montanus’ (1594/95–1638) book on phonetics, De Spreeckonst (1635), which was intended to apply to all languages, could have been an epoch-making standardwork on phonetics, if it had been read and studied more widely. Although he characterized Spreeckonst as a difficult theory he intended it to be an easy textbook. However, Montanus’ terminology made the book almost unreadable. In the first section special attention is paid to Montanus’ idea that all aspects of his object of inquiry (i.e. the spoken language) had to be characterized as aptly and precisely as possible, after having examined the object (a). Next, (in section 2), an attempt is made to clarify Montanus’ opinion that the precise determination of objects (actually, the result of his scientifc inquiry) should function as a perfect didactic tool for his readers (b). Through names’ the reader could learn to produce speech sounds even better than by simply practising their production. Indeed, Spreeckonst was meant to be both a theory and a practical handbook. This can be explained by pointing out the two functions names had: they were instruments of knowledge (a) and instruments of learning (b). As shown in section 3 Montanus was directly influenced by Simon Stevin (1548–1620) with regard to (b). In section 4 it is shown that, in essence, the first idea (a) can be traced back to Socrates’ ideas on names, as Plato had Socrates defend them in his Cratylus. The other idea (b) can be traced back to Cratylos’ ideas on names, which were unfolded and discussed in the same work. Section 5 analyses the sorts of names Montanus actually used. A complete survey of the names of Montanus’ distinctions of speech sounds is presented in this section. In the concluding section (6) an indication is made of the astonishing results of Montanus’ analyses of spoken language.

scholarly journals Textile wing fabric for emergency response UAS

2020 ◽  
Vol 71 (04) ◽  
pp. 321-326
Author(s):  
ADRIAN SĂLIȘTEAN ◽  
CARMEN MIHAI
Keyword(s):  
Emergency Response ◽  
Mechanical Characteristics ◽  
Statistical Data ◽  
Breaking Strength ◽  
Air Permeability ◽  
Experimental Results ◽  
The Other ◽  
Shape Stability ◽  
International Testing

The fabrics used to manufacture parachutes and paragliders must have several specific characteristics: the mass of fabric per unit of surface must be low while the other physical-mechanical characteristics (the axial breaking strength load, the relative and absolute elongation, the tear resistance of the fabric and the assemblies, air permeability) must have high values. The paper deals with the analysis of qualitative aspects of several parachute fabrics that are used as a baseline in the development of a novel fabric. The results of experiments have materialized in statistical data, diagrams and graphs and their interpretation leads to the determination of the fabric variant that best meets the requirements of the destination. The destination is a patent pending inflatable wing design that utilizes a single skin construction and solid reinforcements in the sewing for shape stability. It is worth noting that the experimental results were compared with values indicated in specific international testing norms.

scholarly journals FABRIC FOR SINGLE SKIN TEXTILE WING

2019 ◽  
Vol 2019 ◽  
pp. 220-223
Author(s):  
Adrian SALISTEAN ◽  
Carmen MIHAI ◽  
Irina CRISTIAN ◽  
Daniela FARIMA ◽  
Cristina PIROI
Keyword(s):  
Mechanical Characteristics ◽  
Statistical Data ◽  
Breaking Strength ◽  
Air Permeability ◽  
Experimental Results ◽  
The Other ◽  
Wing Design ◽  
Shape Stability ◽  
International Testing

The fabrics used to make parachutes and paragliders must have the several specific characteristics: the mass of fabric per unit of surface must be low while the other physical- mechanical characteristics (the axial breaking strength load, the relative and absolute elongation, the tear resistance of the fabric and the assemblies, air permeability) must be at a maximum. The paper deals with the analysis of qualitative aspects of several parachute fabrics that are used as a baseline in the development of a novel fabric. The results of experiments have materialized in statistical data, diagrams and graphs and their interpretation leads to the determination of the fabric variant that best meets the requirements of the destination. The destination is a patent pending inflatable wing design that utilizes a single skin construction and solid reinforcements in the sewing for shape stability. It is worth noting that the experimental results were compared with values indicated in specific international testing norms.

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.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

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