hplc measurement
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2020 ◽  
Vol 3 (1) ◽  
pp. 14-22
Author(s):  
Novian Agni Yudhaswara ◽  
Ani Retno Prijanti ◽  
Mohamad Sadikin

Background: Lipoic acid is a substance contained in intra and extracellular that act as a coenzyme of Pyruvate Dehydrogenase, also as an antidote, chelating agent and antioxidant. Measurement of lipoic acid is needed to determine the amount of lipoic acid that performs its functions either as a coenzyme or an antioxidant. Besides, this measurement requires a special tool such as High Performance Liquid Chromatography (HPLC) and a process that is available in rural or simple laboratories.  Objective: A common and easy tool such as a spectrophotometer was conducted and could expected to be a tool of lipoic acid determination in body fluid such as plasma.Methods: Measurement of lipoic acid using spectrophotometry with UV methanol and visible PdCl2 has been tested and compared to HPLC measurement that was valid and reliable in drug measurement or pharmaceutical preparations.Results: Determination of lipoic acid in plasma and leukocytes using PdCl2 produced replicable, reliability and valid result, with high accuracy, precision and was not different from lipoic acid measurement using HPLC, p=0.99. While UV methanol was different compare to HPLC p =0.0001 or was not valid.Conclusion: The measurement of lipoic acid using PdCl2 visible method can be applied to determine the levels of lipoic acid (LA) and DHLA in plasma and equal to HPLC result.


Heliyon ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. e05287
Author(s):  
Zhengzhong Lin ◽  
Shengyang Chen ◽  
Lei Li ◽  
Aihong Peng ◽  
Zhiyong Huang

2020 ◽  
Vol 14 (2) ◽  
pp. 121-133 ◽  
Author(s):  
Maryam Ahankoub ◽  
Gashtasb Mardani ◽  
Payam Ghasemi-Dehkordi ◽  
Ameneh Mehri-Ghahfarrokhi ◽  
Abbas Doosti ◽  
...  

Background: Genetically engineered microorganisms (GEMs) can be used for bioremediation of the biological pollutants into nonhazardous or less-hazardous substances, at lower cost. Polycyclic aromatic hydrocarbons (PAHs) are one of these contaminants that associated with a risk of human cancer development. Genetically engineered E. coli that encoded catechol 2,3- dioxygenase (C230) was created and investigated its ability to biodecomposition of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC) measurement. We revised patents documents relating to the use of GEMs for bioremediation. This approach have already been done in others studies although using other genes codifying for same catechol degradation approach. Objective: In this study, we investigated biodecomposition of phenanthrene and pyrene by a genetically engineered Escherichia coli. Methods: Briefly, following the cloning of C230 gene (nahH) into pUC18 vector and transformation into E. coli Top10F, the complementary tests, including catalase, oxidase and PCR were used as on isolated bacteria from spiked soil. Results: The results of HPLC measurement showed that in spiked soil containing engineered E. coli, biodegradation of phenanthrene and pyrene comparing to autoclaved soil that inoculated by wild type of E. coli and normal soil group with natural microbial flora, were statistically significant (p<0.05). Moreover, catalase test was positive while the oxidase tests were negative. Conclusion: These findings indicated that genetically manipulated E. coli can provide an effective clean-up process on PAH compounds and it is useful for bioremediation of environmental pollution with petrochemical products.


Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 819 ◽  
Author(s):  
Chenxu Du ◽  
Chaoqun Ma ◽  
Jiao Gu ◽  
Lei Li ◽  
Guoqing Chen

A rapid, selective and sensitive method for the detection of caffeine in tea infusion and tea beverages are proposed by using 3,5-diaminobenzoic acid as a fluorescent probe. The 3,5-diaminobenzoic acid emits strong fluorescence around 410 nm under the excitation of light at 280 nm. Both the molecular electrostatic potential analysis and fluorescent lifetime measurement proved that the existence of caffeine can quench the fluorescence of 3,5-diaminobenzoic acid. Under the optimal experimental parameters, the 3,5-diaminobenzoic acid was used as a fluorescent probe to detect the caffeine aqueous solution. There exists a good linear relationship between the fluorescence quenching of the fluorescent probe and the concentration of caffeine in the range of 0.1–100 μM, with recovery within 96.0 to 106.2%, while the limit of detection of caffeine is 0.03 μM. This method shows a high selectivity for caffeine. The caffeine content in different tea infusions and tea beverages has been determined and compared with the results from HPLC measurement.


OENO One ◽  
2017 ◽  
Vol 51 (1) ◽  
Author(s):  
Amélie RABOT

<p>Aim: The importance of phenolic maturity (depending on tannins and anthocyans) of the grape is crucial at harvest and determines the final quality of wine. The work presented here aims to characterize the evolution of phenolic maturity of seeds for 3 varieties combining macroscopic analysis and biochemical analyzes of these tannins at phenological stages of interest.</p><p>Methods and results: Using R software for macroscopic analyzes have been shown that the color varies dramatically (from green to dark brown) in the two months between the bunch closure and maturity. Biochemical analysis (HPLC measurement) shows that tannins in seeds are increasing from bunch closure to early veraison and decrease after this step until maturity.</p><p>Conclusion: All together these results have shown that the color variation is correlated to the tannins content in the seeds.</p><p>Significance of the study: Nowadays, no easy ways of prediction of phenolic maturity are known. The aim of this work is to use these results (usually considered independently) to have an knowledge of seed level of phenolic maturity necessary without biochemical analysis to establish a date of great harvest for the most favorable conditions for the extraction of tannins required for the organoleptic quality of a wine .The originality of this work is to use the combined visual seeds and its biochemical composition in tannins (correlation established by CPA). Forward, these results will help to develop a decision support tool based on simply system to acquiring seed image easily usable by winemakers.</p>


Genetika ◽  
2016 ◽  
Vol 48 (3) ◽  
pp. 837-858 ◽  
Author(s):  
Gashtasb Mardani ◽  
Amir Mahvi ◽  
Morteza Hashemzadeh-Chaleshtori ◽  
Simin Nasseri ◽  
Mohammad Dehghani ◽  
...  

Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs) but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC) method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O) was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p<0.05). Although adding N and P chemical nutrients on degradation ability of phenanthrene and pyrene by engineered P. putida in soil were not statistically significant (p>0.05) but it was few impact on this process (more than 2%). Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted environments.


Author(s):  
Nikolai L. Chepelev ◽  
Dean A. Kennedy ◽  
Remi Gagné ◽  
Taryn White ◽  
Alexandra S. Long ◽  
...  

2013 ◽  
Vol 41 (2) ◽  
pp. 582 ◽  
Author(s):  
Danijela PAVLOVIC ◽  
Sava VRBNICANIN ◽  
Carl REINHARDT

Glyphosate may cause injury to non-target plants. The first detectable symptom after glyphosate treatment is the growth inhibition, followed by noticeable yellowing (chlorosis) of the treated tissue. Five to ten days after the treatment, the chlorosis turns into necrosis and the plants begin to die. Greenhouse research was conducted in 2007 to investigate the response of glyphosate resistant (GR) soybeans PAN 520 line and non-glyphosate resistant EGRET line of soybeans to glyphosate trimesium sulphosate and to evaluate soybeans injury to help in weed resistance detection. The methods used to detect changes were dose response test, HPLC measurement based on glyphosate induced accumulation of shikimate, and morpho-anatomical changes (light and electron microscopy). Damaged chloroplasts are a clear indication of a glyphosate injury. If the injury rating is related to increased shikimate levels, there is greater certainty that differences among biotypes are due to glyphosate tolerance.


2013 ◽  
Vol 85 (3) ◽  
pp. 1657-1664 ◽  
Author(s):  
Daniel G. Burke ◽  
Lianhua Dong ◽  
Somanath Bhat ◽  
Michael Forbes-Smith ◽  
Shuang Fu ◽  
...  

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