Quantitative extraction and determination of elemental sulfur and stoichiometric oxidation of sulfide to elemental sulfur by Thiobacillus thiooxidans

1993 ◽  
Vol 39 (12) ◽  
pp. 1166-1168 ◽  
Author(s):  
C. W. Chan ◽  
Isamu Suzuki
Keyword(s):  
Quantitative Analysis ◽  
Biological System ◽  
Analytical Method ◽  
Elemental Sulfur ◽  
Sulfide Oxidation ◽  
Thiobacillus Thiooxidans ◽  
Color Formation ◽  
Ferric Thiocyanate ◽  
Quantitative Extraction

A sensitive and quantitative analytical method for determining elemental sulfur in a biological system was developed. Elemental sulfur was determined after extraction with petroleum ether by cyanolysis and ferric thiocyanate color formation in acetone. The method was successfully applied to show that sulfide was oxidized by Thiobacillus thiooxidans to elemental sulfur nearly stoichiometrically when further oxidation of elemental sulfur was inhibited by N-ethylmaleimide.Key words: elemental sulfur, quantitative analysis, sulfide oxidation, Thiobacillus thiooxidans.

The Determination of Zinc Oxide in Rubber Vulcanizates by X-Ray Diffraction

1960 ◽  
Vol 33 (3) ◽  
pp. 890-898
Author(s):  
Stephen H. Laning ◽  
Melvin P. Wagner ◽  
John W. Sellers
Keyword(s):  
Zinc Oxide ◽  
Quantitative Analysis ◽  
Analytical Method ◽  
Direct Determination ◽  
Zinc Stearate ◽  
Photographic Film ◽  
Reaction Products ◽  
X Ray

Abstract Zinc oxide is a necessary component in most accelerator-sulfur vulcanization systems. While it is not an accelerator, its presence leads to increased modulus, i.e., tighter cures. The manner in which it can effect this better cure is not completely clear. Some insight into the role of zinc oxide has been gained through the analysis of the vulcanizate for reaction products of zinc, such as zinc stearate, the zinc salts of the accelerators, and zinc sulfide. However, these products may not account for all of the zinc oxide which has reacted. An analytical method for the direct determination of unreacted zinc oxide in vulcanizates was therefore needed. The determination of zinc oxide in rubber vulcanizates has received scant attention. Wet-chemical techniques for analysis of the sample after ashing provide only the total amount of zinc from which the amount of unreacted zinc oxide cannot be determined. Endter has reported the use of the Debye-Scherrer x-ray technique for the identification of zinc oxide in rubber samples. While similar to the method developed in this laboratory, Endter employed photographic film for recording the diffraction pattern, and special sample preparation was required to accommodate the photographic technique. This method was satisfactory for qualitative identification of zinc oxide, but was difficult to use for quantitative analysis. Subsequent to this investigation Hagino et al. described the use of x-ray diffractometry for the determination of the mixing ratio of ingredients compounded in rubber. This method was also suggested for the quantitative analysis of zinc oxide, but no studies were reported. During a study in this laboratory to determine the role of zinc oxide in the vulcanization of rubber, a new analytical method, based on x-ray diffractometry, was developed. The method was rapid, nondestructive, and simple. The data were reliable and accurate.

Quantitative analysis of fourteen synthetic dyes in jelly and gummy candy by ultra performance liquid chromatography

2014 ◽  
Vol 6 (15) ◽  
pp. 5872-5878 ◽  
Author(s):  
Yi Yang ◽  
Jing Zhang ◽  
Bing Shao
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Analysis ◽  
Simultaneous Determination ◽  
Analytical Method ◽  
Ultra Performance Liquid Chromatography ◽  
Array Detector ◽  
Synthetic Dyes ◽  
Photodiode Array Detector ◽  
Photodiode Array

An analytical method was developed for the simultaneous determination of 14 dyes in jelly and gummy candy using ultra performance liquid chromatography with a photodiode array detector.

scholarly journals Method Validation and Measurement Uncertainty Determination of Ethoxyquin and Antioxidant Activity in Paprika Seasonings and Paprika Sauces Frequently Consumed in South Korea

Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 50
Author(s):  
Gill-Woong Jang ◽  
Sun-Il Choi ◽  
Xionggao Han ◽  
Xiao Men ◽  
Hee-Yeon Kwon ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Liquid Chromatography ◽  
Quantitative Analysis ◽  
South Korea ◽  
Analytical Method ◽  
High Performance ◽  
Trade Association ◽  
Relative Standard ◽  
Photodiode Array

In this study, we investigated and validated a method for the quantitative analysis of ethoxyquin in paprika seasonings and sauces, which are frequently consumed in South Korea. Using this analytical method, we were able to confirm the presence of ethoxyquin under optimized high-performance liquid chromatography/photodiode array (HPLC-PDA) and liquid chromatography with tandem mass spectrometry conditions. Additionally, the antioxidant activity of ethoxyquin was assessed using the American Spice Trade Association values and its residual levels in paprika seasoning samples. The HPLC-PDA limits of detection and quantification for ethoxyquin were found to be 0.26 and 0.79 μg/mL, and 0.33 to 1.00 μg/mL, and the recoveries of ethoxyquin ranged from 86.75 to 101.70%, with relative standard deviations ranging from 0.31% to 3.59%. These results indicated that the analytical method in this study should be appropriate for the quantitative analysis of ethoxyquin in paprika seasoning and sauce matrices.

DEVELOPMENT OF DROPLET-PIXE SYSTEM FOR ENVIRONMENTAL MONITORING SAMPLES

2005 ◽  
Vol 15 (03n04) ◽  
pp. 293-299 ◽  
Author(s):  
H. IMASEKI ◽  
K. ISHII ◽  
T. ISHIKAWA ◽  
H. ISO ◽  
T. SHINOMIYA ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Sample Preparation ◽  
Environmental Monitoring ◽  
Analytical Method ◽  
Atmospheric Condition ◽  
Preparation Process ◽  
Pixe Analysis ◽  
Elemental Abundances ◽  
Liquid Samples

PIXE is a trace analytical method. During the sample preparation process for PIXE analysis, there may be loss of element due to sublimation or evaporation that must be considered for quantitative analysis. To avoid such problems, suitable droplet PIXE system has been developed for determination of elemental abundances of liquid samples in atmospheric condition. The system has several dripping modes in order to enhance advantage of dripping method over static liquid target method. The droplet-PIXE system has been applied to a few case studies. Its advantages over other PIXE system will be discussed in this paper.

Determination of Ethyl Carbamate in Chinese Yellow Rice Wine by Diatomaceous Earth Extraction and GC/MS Method

2015 ◽  
Vol 98 (3) ◽  
pp. 834-838 ◽  
Author(s):  
Pinggu Wu ◽  
Liqun Zhang ◽  
Xianghong Shen ◽  
Liyuan Wang ◽  
Yan Zou ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Quantitative Determination ◽  
Analytical Method ◽  
Diatomaceous Earth ◽  
Capillary Column ◽  
Internal Standard ◽  
Ethyl Carbamate ◽  
Rice Wine ◽  
Average Recovery

Abstract A sensitive and rapid analytical method based on alkaline diatomaceous earth extraction followed by GC/MS was developed for the quantitative determination of the toxic contaminant ethyl carbamate (EC) in yellow rice wines. The optimal extraction conditions were investigated. With the application of diatomaceous earth extraction, the damage of organic acids to the capillary column was greatly reduced. By using d5-EC as an internal standard for quantitative analysis of EC, the linearity of the calibration curves was good between 10 and 1000 ng/mL. The LOD and LOQ were 1.7 and 5.0 μg/kg, respectively. The spiked level of EC was 5.0–300 μg/kg, and the average recovery of the spikes was between 78.4 and 98.2%, with an RSD between 4.3 and 8.3%. Upon validation by five laboratories when spiked with 50, 100, and 300 μg/kg, the average respective recoveries were 102.9, 102.2, and 98.7% with a RSD between 0.7 and 8.1%. The validation results demonstrated that the method is fast, simple, selective, and suitable for the determination of EC in yellow rice wines.

An Improved Quantitative Image Analyser

1977 ◽  
Vol 35 ◽  
pp. 226-227
Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor
Keyword(s):  
Feature Extraction ◽  
Quantitative Analysis ◽  
Frequency Content ◽  
General Sense ◽  
Physical Measurements ◽  
Quantitative Image ◽  
Image Analyser ◽  
Automatic Methods ◽  
Quantitative Results

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

Application of EDS Technique for OSP Film Thickness Measurement

2006 ◽  
Author(s):  
Prong Kongsubto ◽  
Sirarat Kongwudthiti
Keyword(s):  
Thin Film ◽  
Quantitative Analysis ◽  
Joint Strength ◽  
Critical Factor ◽  
Thickness Measurement ◽  
Ic Manufacturing ◽  
And Control ◽  
Film Thickness Measurement ◽  
Non Destructive

Abstract Organic solderability preservatives (OSPs) pad is one of the pad finishing technologies where Cu pad is coated with a thin film of an organic material to protect Cu from oxidation during storage and many processes in IC manufacturing. Thickness of OSP film is a critical factor that we have to consider and control in order to achieve desirable joint strength. Until now, no non-destructive technique has been proposed to measure OSP thickness on substrate. This paper reports about the development of EDS technique for estimating OSP thickness, starting with determination of the EDS parameter followed by establishing the correlation between C/Cu ratio and OSP thickness and, finally, evaluating the accuracy of the EDS technique for OSP thickness measurement. EDS quantitative analysis was proved that it can be utilized for OSP thickness estimation.

Sign in / Sign up

Export Citation Format

Share Document