Experimental Investigation on Determination of Chitosan by Spectrophotometry

2012 ◽  
Vol 554-556 ◽  
pp. 1895-1900 ◽  
Author(s):  
Si Hui Wu ◽  
Song Yan Hu ◽  
Gui Dong Huang ◽  
Wei Shan Pan ◽  
Cheng Lu Yu ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Sulfuric Acid ◽  
Alcohol Solution ◽  
Alkaline Condition ◽  
Boiling Water Bath ◽  
Optimal Conditions ◽  
Average Recovery ◽  
Mixed Acid ◽  
Ultrasound Assisted

Chitosan is a natural basic polysaccharide, currently which have no a very effective way to determine its content. In this paper, we used mixed acid and ultrasound-assisted with chitosan which hydrolyzed into glucosamine, under alkaline condition acetyl acetone may react with paradimethylaminobenzaldehyde acid alcohol solution to form red compound, which was measured at 525nm by spectrophotometry. More appropriate technological conditions have been determined. The results showed that the optimal conditions for quantity of chitosan was 2mg, 0.168mol/L hydrochloric acid was 0.8ml, 75% sulfuric acid was 3.5ml, in boiling water bath for 30min, supersonic for 60min at 50 °C, the average recovery was 96.9±3.24%, the content of chitosan was 87.89±1.02%, the production rate of chitosan was 84.79±0.99%. The results show that the mentioned method is easy and effective for the quantitative analysis of chitosan by spectrophotometry.

Study on the Determination of Manganese in Alloy Steel Materials by Spectrophotometry

2013 ◽  
Vol 803 ◽  
pp. 196-199
Author(s):  
Mei Mei Li ◽  
Nai Jun Li
Keyword(s):  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Alloy Steel ◽  
Acid System ◽  
Mixed Acid ◽  
Relative Standard ◽  
Beer's Law ◽  
Beer’S Law ◽  
Standard Deviations

With samples decomposed by mixed acid of sulfuric acid-phosphoric acid, manganese in alloy steel was determined by periodate spectrophotometry. The acid system for dissolving samples was established, and 525 nm as the optimal measuring wavelength was selected. The results showed that Beer's law was obeyed in range of 0 to 36μg/mL for manganese (II). The relative standard deviations were between 0.6% to 2.0%(n=6). The recoveries of samples were between 95.1to 101.4%.

Determination of Mercury in Biological Materials

1970 ◽  
Vol 53 (6) ◽  
pp. 1172-1175 ◽  
Author(s):  
M T Jeffus ◽  
J S Elkins ◽  
C T Kenner
Keyword(s):  
Sulfuric Acid ◽  
Standard Deviation ◽  
Nitric Acid ◽  
Biological Samples ◽  
Room Temperature ◽  
Gold Foil ◽  
Average Recovery ◽  
Average Value ◽  
The Difference

Abstract Mercury in biological samples is determined by digestion in nitric acid, sulfuric acid, and permanganate, followed by reduction and aeration for measurement by atomic absorption at room temperature. The average recovery is 95.8% with a standard deviation of 13.3%. The standard deviation, calculated from the difference between duplicates of 23 samples, is 0.063 μg mercury, which represents 9.4% of the average value of the samples. The method is simple and requires approximately 4 hr for completion. Mercury can be confirmed by adsorption on gold foil after maximum absorbance has been obtained during aeration.

Stability-Indicating Spectrophotometry Determination of Morphine in Injectable Solutions Containing Bisulfite

1974 ◽  
Vol 57 (3) ◽  
pp. 738-740
Author(s):  
Harvey K Hundley ◽  
Gabriel D Castillo
Keyword(s):  
Sulfuric Acid ◽  
Ion Pair ◽  
Oxidation Products ◽  
Commercial Preparation ◽  
Average Recovery ◽  
Dilute Sulfuric Acid ◽  
Chromatographic Procedure ◽  
Ether Solution ◽  
Induced Decomposition

Abstract Morphine in injectable preparations mar undergo reaction with bisulfite when this is used as an antioxidant in the formulation. A simple chromatographic procedure has been developed for the separation of morphine from its oxidation products and from the morphine-bisulfite interaction products. Neutral or acidic impurities are removed from a pH 4.3 buffered sample by elution of a partition chromatographic column with ether. An ether solution of di-(2- ethylhexyl) phosphoric acid is then used to elute the morphine as the cationic component of the ion pair. This fraction is extracted with dilute sulfuric acid to dissociate the ion pair and transfer the morphine to the acid solution for spectrophotometric determination. Multiple analyses of a commercial morphine sulfate formulation gave 101.2±0.3% of declared. Assays by 5 analysts of another commercial preparation and a laboratory preparation gave, respectively, an average of 99.6±2.7% of declared and an average recovery of 90.4±0.5%. The latter, containing 7 mg bisulfite/ml, or 7 times as much as the commercial formulations, shows significant bisulfite-induced decomposition.

Synthesis of rGO/TiO2/CdS Nanocomposites and its Enhanced Photoelectrochemical Performance in Determination of Parathion-Methyl

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850054
Author(s):  
Jian-Jun Shi ◽  
Yan Wang ◽  
Li-Rong Meng ◽  
Jing-Chun Zhu ◽  
Rui-Wen Shu ◽  
...  
Keyword(s):  
Solvothermal Method ◽  
High Sensitivity ◽  
Alkaline Condition ◽  
Optimal Conditions ◽  
Excellent Performance ◽  
Photoelectrochemical Performance ◽  
Sensing System ◽  
The Matrix ◽  
Cds Nanocomposites

A photoelectrochemical (PEC) sensor for the determination of organophosphate pesticides (OPs) was developed based on rGO/TiO2/CdS photoactive nanomaterials. The rGO/TiO2/CdS nanocomposites were prepared by solvothermal method and electrochemical deposition technique successively. The morphologies and structures of the as-prepared nanocomposites were extensively investigated by SEM and XRD. In alkaline condition, p-nitrophenol as the hydrolysate of parathion-methyl (PM) could be obtained by a simple hydrolyzation process. Under optimal conditions, the rGO/TiO2/CdS NPs modified ITO electrode exhibited a good PEC performance toward the hydrolysate of PM. The photocurrent intensity was enhanced with the increase of the concentration of the hydrolysate of PM. The proposed PEC method could detect PM in the range from 0.05[Formula: see text]nmol L[Formula: see text] to 10[Formula: see text]nmol L[Formula: see text] with a detection limit of 0.02[Formula: see text]nmol L[Formula: see text] ([Formula: see text]). Thus, the excellent performance of the rGO/TiO2/CdS nanocomposites serve as the matrix of the sensor, which provides a new way for the fabrication of high-sensitivity PEC sensing system.

Gallium Arsenide Integrated Circuits Decapsulation Technique Using Mixed Acid Chemistry For Die-Level Failure Analysis

2018 ◽  
Author(s):  
Harold Jeffrey M. Consigo ◽  
Ricardo S. Calanog ◽  
Melissa O. Caseria
Keyword(s):  
Gallium Arsenide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
Mixed Acid ◽  
Optimum Parameters ◽  
Plastic Package ◽  
Fuming Nitric Acid ◽  
Concentrated Sulfuric Acid

Abstract Gallium Arsenide (GaAs) integrated circuits have become popular these days with superior speed/power products that permit the development of systems that otherwise would have made it impossible or impractical to construct using silicon semiconductors. However, failure analysis remains to be very challenging as GaAs material is easily dissolved when it is reacted with fuming nitric acid used during standard decapsulation process. By utilizing enhanced chemical decapsulation technique with mixture of fuming nitric acid and concentrated sulfuric acid at a low temperature backed with statistical analysis, successful plastic package decapsulation happens to be reproducible mainly for die level failure analysis purposes. The paper aims to develop a chemical decapsulation process with optimum parameters needed to successfully decapsulate plastic molded GaAs integrated circuits for die level failure analysis.

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