Paper No P15: Enhancement of Extraction Efficiency in OLED with Multi-Cathode Structure Prepared on a Plastic Substrate

2015 ◽  
Vol 46 (S1) ◽  
pp. 82-82
Author(s):  
Akiyoshi Mikami ◽  
Shuhei Doi
Keyword(s):  
Extraction Efficiency ◽  
Plastic Substrate ◽  
Cathode Structure

SKRINING FITOKIMIA DAN UJI AKTIVITAS ANTIOKSIDAN DAN ANTITUMOR 20 TUMBUHAN OBAT ASAL KABUPATEN MANOKWARI

2008 ◽  
Vol 7 (1) ◽  
Author(s):  
Bimo Budi Santoso
Keyword(s):  
Antioxidant Activity ◽  
Medicinal Plants ◽  
Antitumor Activity ◽  
Traditional Method ◽  
Extraction Efficiency ◽  
Phenolic Content ◽  
Antioxidant Activities ◽  
Total Phenolic ◽  
Phenolic Contents ◽  
Total Phenolic Contents

<strong><em>Flavanoid, steroid, and terpenoid contents of 20 Manokwari medicinal plants were analyzed.  The antioxidant activity, total phenolic contents and antitumor activity of 20 Manokwari medicinal plants were also evaluated. The result shows that 83% positif to flavanoid test, 59% positif to terpenoid test and only 25% positif steroid. Antioxidant activity and total phenolic contents evaluated using Ferric Thiocianate (FTC) and Folin-Ciocalteu methods respectively. Antioxidant activity and total phenolic contents of medicinal plants were extracted by the traditional method, boiling in water and also in 80% methanol. Twenty plants evaluated in both exstracts have significantly varies of antioxidant activities and phenolic contents,  A significant and linier correlation coefficient between the antioxidant activity and the total phenolic content was found in both aqueous (R<sup>2</sup>= 0,77) and methanol (R<sup>2</sup> = 0,85). Antitumor activity was tested using cell maurine P-388 and only 2 of medicinal plants are active to inhibit cell maurine P-388. Comparing extraction efficiency of the two methods, the methanol extracted phenolic compounds more efficiently, and antioxidant activity of the extract was higher.</em></strong>

ZnO Nano-arrays on High Power Blue LED Chip for Enhanced Light Extraction Efficiency

2012 ◽  
Vol 27 (7) ◽  
pp. 716-720
Author(s):  
Bing XU ◽  
Jun-Liang ZHAO ◽  
Jian-Ming ZHANG ◽  
Xiao-Wei SUN ◽  
Fu-Wei ZHUGE ◽  
...  
Keyword(s):  
High Power ◽  
Extraction Efficiency ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Blue Led

Quantitative GC-FID and UHPLC-DAD Evaluation of Bioactive Compounds Extracted from Ginkgo biloba

2020 ◽  
Vol 16 (7) ◽  
pp. 893-904
Author(s):  
Alessandra von Ahn ◽  
João Henrique Z. dos Santos
Keyword(s):  
Ginkgo Biloba ◽  
Extraction Efficiency ◽  
Extraction Methods ◽  
Ginkgo Biloba Extract ◽  
Previous Method ◽  
Array Detector ◽  
Ginkgolide B ◽  
Detection Techniques ◽  
Ginkgolide A ◽  
Terpene Trilactones

Background: The official compendium of the quantification of ginkgo flavonoids from Ginkgo biloba extract has been proposed using HPLC. The drawbacks of this technique appear to be due to the restricted efficiency in terms of the recovery results and suitability of the system for the quantification of these compounds. This study investigated the potential advantages and limitations of the development of efficient extraction methods for the recovery of flavonol glycosides (quercetin, kaempferol and isorhamnetin) and terpene trilactones (bilobalide, ginkgolide A, ginkgolide B and ginkgolide C) using extraction, quantification and detection techniques, namely, GC-FID and UHPLC-DAD, which are alternatives to those techniques available in the literature. Methods: Two different extraction methodologies have been developed for the determination of flavonoids (quercetin, kaempferol and isorhamnetin) and terpene trilactones (bilobalide, ginkgolide A, ginkgolide B and ginkgolide C) using ultra-high-pressure liquid chromatography coupled to a diode array detector and gas chromatography coupled to a flame ionization detector. Results: In this study, the Ginkgo biloba extract mass, hydrolysis preparation method (with or without reflux), and volume of the extraction solution seemed to affect the ginkgo flavonoid recovery. The UHPLC-based method exhibited higher extraction efficiency for ginkgo flavonoid quantification compared to the pharmacopoeial method. The developed method exhibited higher extraction efficiency for terpene quantification compared to the previous method that used extractive solution without pH adjustment, with less time of extraction and less amount of the sample and organic solvent aliquots. Conclusion: The UHPLC and GC analysis methods established in this study are both effective and efficient. These methods may improve the quality control procedures for ginkgo extract and commercial products available in today´s natural health product market. The results indicate that redeveloped extraction methods can be a viable alternative to traditional extraction methods.

Facile and Fast Detection of Genistein in Derris scandens by Square Wave Voltammetry using a Cobalt(II) Phthalocyanine-Modified Screen-Printed Electrochemical Sensor

2020 ◽  
Vol 16 (3) ◽  
pp. 341-348
Author(s):  
Surinya Traipop ◽  
Suchada Chuanuwatanakul ◽  
Orawon Chailapakul ◽  
Eakkasit Punrat
Keyword(s):  
Electrochemical Sensor ◽  
Square Wave Voltammetry ◽  
Silver Chloride ◽  
Reference Electrode ◽  
High Sensitivity ◽  
Plastic Substrate ◽  
Fast Analysis ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Screen Printed

Background: Recently, Derris scandens, a Thai herbal medicine with anti-inflammatory activity, is widely used as beverage and supplementary food. When the traditional medicine is a choice for health therapy, the simple and reliable equipment is required to control the suitable consuming amount of the active component. Objective: To develop the electrochemical sensor for genistein determination in Derris scandens with high sensitivity and rapid operation. Methods: An in-house screen-printed electrochemical sensor consisting of a three-electrode system was developed for genistein determination. A silver/silver chloride (Ag/AgCl) reference electrode, a carbon counter electrode and a carbon working electrode were prepared on a 0.3-mm-thick plastic substrate by the screen-printing technique using conductive ink. The dimensions of each sensor were 2.5×1.0 cm. Only 50 µL of sample solution was required on this device for the determination of genistein concentration by rapid response square wave voltammetry. Results: The oxidation peak of genistein appeared with good response in acidic media at a peak potential of 0.6 V. Moreover, the signal was enhanced by modifying the conductive carbon ink with cobalt( II) phthalocyanine. Under the optimized conditions, the linear range was found to be 2.5-150 µM and the detection limit was 1.5 µM. Moreover, the small volume extraction was successfully developed without any further pre-concentration. This proposed method was applied to determine genistein in Derris scandens with satisfying results. Conclusion: The proposed method is promising as an alternative method for genistein determination with facile and fast analysis.

Comparison of extraction efficiency of various methods to extract L-DOPA from Mucuna pruriens (L.) DC.

2017 ◽  
Vol 6 (04) ◽  
pp. 5343
Author(s):  
Ragni Vora ◽  
Ambika N. Joshi* ◽  
Nitesh C. Joshi
Keyword(s):  
Extraction Efficiency ◽  
Soxhlet Extraction ◽  
Extraction Methods ◽  
Mucuna Pruriens ◽  
Water Mixture ◽  
Uv Detector ◽  
Pharmacological Activities ◽  
Hplc Mobile Phase ◽  
Plant Sources ◽  
Seed Extracts

Mucuna pruriens seeds are noted to be a natural source of L-DOPA and are also used as a substitute for the synthetic L-DOPA. In the present study; attempts are made to develop suitable method(s) for extraction of L-DOPA from the powdered seeds of Mucuna pruriens using different solvents and conditions. The Seed powder was subjected to 7 different extraction methods and Method 1 was subjected to various solvent concentrations. Some methods used de-fatting procedure, either the method was cold maceration or in high temperature. Soxhlet extraction was also used in one of the extraction methods. All the extracts were analyzed using RP-HPLC. Mobile Phase used was Water: Methanol: AcetoNitrile (100:60:40) (v/v) containing 0.2% Triethylamine, pH = 3.3 and monitored at 280 nm with variable wavelength UV detector. The extraction was best with Methanol Water mixture in a cold maceration technique and overall gives good extraction efficiency of 13.36 % L-DOPA and id the best method giving highest extraction efficiency. The De-fatting method was the 2nd best methods giving approximately 8.8% L-DOPA and Method 5 viz, heat reflux method gives 8.7% L-DOPA making it the 3rd best method. There are not many studies done for optimization of extraction technique for L-DOPA despite an extensive work is reported for isolation, identification and pharmacological activities of L-DOPA from various plant sources. Keeping this in view, present investigation was done to study the extraction efficiency of various extraction methods of L-DOPA content in seed extracts of Mucuna pruriens and compare it.

Comparison of Procedures for Isolation of Monoterpene Hydrocarbons from Fresh Needles of Picea abies and Picea omorica

2000 ◽  
Vol 65 (7) ◽  
pp. 1073-1081 ◽  
Author(s):  
Valerie Holubová ◽  
Iva Chvílíčková ◽  
Vlastimil Kubáň
Keyword(s):  
Picea Abies ◽  
Liquid Nitrogen ◽  
Steam Distillation ◽  
Extraction Efficiency ◽  
Total Content ◽  
Storage Conditions ◽  
Fresh Weight ◽  
Hexane Extraction ◽  
Monoterpene Hydrocarbons ◽  
And Storage

Extraction procedures (steam distillation, supercritical fluid extraction and solvent extraction) for isolation of monoterpene hydrocarbons from fresh needles of Picea abies and Picea omorica were optimised. The procedures were compared with the aim of minimizing consumption of needles and improving the extraction efficiency and repeatability. An influence of homogenisation procedures and storage conditions (liquid nitrogen, -18 and 4 °C) on the total content and composition of essential oils was studied. Cryogenic grinding (liquid nitrogen) combined with the extraction with cold hexane (extraction time 2 h) and subsequent GC-MS determination in freshly homogenised needles gives the best results (1.5-4 times better extraction efficiency, RSD < 10% for P. abies and < 25% for P. omorica). Limits of detections (3 S/N) for individual monoterpene hydrocarbons from units to tens of ng/g and recoveries 97.2-101.4% were found in fresh needles (calculated to fresh weight). While cooling to 4 °C is unacceptable, freezing at -18 °C for the period of 18 days in the dark gives also good results.

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