scholarly journals Detection and Quantitative Analysis for 2-Thiobarbituric Acid Utilizing Uv-Visible Spectrophotometer

2013 ◽  
Vol 1 (1) ◽  
pp. 10-14 ◽  
Author(s):  
Ronald Bartzatt ◽  
Maggie Bartlett ◽  
Nancy Handler
Author(s):  
Lorenzo Casimiro ◽  
Leonardo Andreoni ◽  
Jessica Groppi ◽  
Alberto Credi ◽  
Rémi Métivier ◽  
...  

AbstractChemical actinometers are a useful tool in photochemistry, which allows to measure the photon flux of a light source to carry out quantitative analysis on photoreactions. The most commonly employed actinometers so far show minor drawbacks, such as difficult data treatment, parasite reactions, low stability or impossible reset. We propose herewith the use of 4,4′-dimethylazobenzene as a chemical actinometer. This compound undergoes a clean and efficient E/Z isomerization, approaching total conversion upon irradiation at 365 nm. Thanks to its properties, it can be used to determine the photon flux in the UV–visible region, with simple experimental methods and data treatment, and with the possibility to be reused after photochemical or thermal reset. Graphical abstract


2021 ◽  
Vol 4 (2) ◽  
pp. 1-7
Author(s):  
Irman Idrus ◽  
Sabda Wahab ◽  
Andi Fitrah Nugraha ◽  
Syaiful Bachri

South Konawe District at Southeast Sulawesi Province is a producer of agriculture such as Papaya fruit ranging from 1168 quintals each year. Papaya fruit contains β-carotene which plays an important role in the formation of vitamin A in the body. This research was conducted to determine the β-carotene content of papaya fruit by using variables planting method, fruitage, and fruit condition. The mashed fruit was extracted using n-hexane: acetone: ethanol (2: 1: 1) v/v, then separated from polar and non-polar solutions. Qualitative analysis was carried out using the Carr-Price method and quantitative analysis or determination of β-carotene levels using the UV-Visible spectrophotometric method λ = 452.0 nm. The qualitative test results showed that the papaya fruit in the papaya fruit obtained by cultivation and growing wild with each variable half-ripe, ripe, and not fresh papaya identified the presence of β-carotene. The results of quantitative analysis of β-carotene levels in cultivated papaya fruit were 1.76 μL, half-ripe 1.32 μL, and cultivated young papaya 1.22 μL. In wild ripe papaya 1.75 μL, wild half-ripe papaya 1.3 μL and wild young papaya 1.21 μL. There is an effect of each test parameter starting from the parameters of planting method, fruitage, and fruit condition on β-carotene content in papaya fruit.


1994 ◽  
Vol 359 ◽  
Author(s):  
E. Pasqualini ◽  
C. Podesta ◽  
A. GarcÍa ◽  
A. Rafael ◽  
S. Dengra ◽  
...  

ABSTRACTThe reaction chamber in the arc production of fullerenes was redesigned with a nozzle surrounding the decomposition zone to allow for clean collection of soot in a filtering cartridge. Quantitative analysis in the region of 300–430 nm in UV-visible spectra permits determination of the abundance of C60 and C70 in the soot. Calibrated curves of absorptivity for both pure fullerenes were employed. In equivalent conditions of current and pressure, electrographites of different origins have different decomposition rates and yields. A mechanism to interpret the cathodic deposit formation is proposed. Decomposition inside a closed cathodic cylinder yields 100% deposit.


Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor

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.


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