scholarly journals Monitoring Organic Reactions by Micellar Electrokinetic Chromatography

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Chun Yang ◽  
Chunyang Chang ◽  
Jun Wang ◽  
Qishu Qu ◽  
Xiaoya Hu ◽  
...  
Keyword(s):  
Real Time ◽  
Glycidyl Methacrylate ◽  
Micellar Electrokinetic Chromatography ◽  
Low Cost ◽  
Direct Synthesis ◽  
Organic Reactions ◽  
Electrokinetic Chromatography ◽  
Allyl Amine

A method was established to monitor organic reactions by micellar capillary electrokinetic chromatography (MEKC). After optimizing conditions such as the composition of the solvents, the surfactant, and the apparent pH (pH*) of the system, the method was utilized to analyze the reaction of glycidyl methacrylate (GMA) and allyl amine. The main products were identified in the electropherograms. The reaction procedure was monitored in real time. This method was found to have common applicability, being able to separate and detect nonaqueous soluble, nonionic, and low-UV-Vis absorbance compounds. It provides a rapid and low-cost way to understand organic reactions and to direct synthesis works.

scholarly journals Analysis of Seven Biogenic Amines and Two Amino Acids in Wines Using Micellar Electrokinetic Chromatography

2019 ◽  
Vol 9 (6) ◽  
pp. 1193 ◽  
Author(s):  
Chih-Ying Huang ◽  
Yu-Xian Wang ◽  
Xin-Zhi Wang ◽  
Cho-Chun Hu ◽  
Tai-Chia Chiu
Keyword(s):  
Amino Acids ◽  
Biogenic Amines ◽  
Micellar Electrokinetic Chromatography ◽  
Low Cost ◽  
Background Electrolyte ◽  
Sodium Dodecyl ◽  
Fast Method ◽  
Electrokinetic Chromatography ◽  
Optimal Separation

A low-cost, simple, and fast method utilizing micellar electrokinetic chromatography for the simultaneous determination of seven biogenic amines and two amino acids was developed. A background electrolyte containing 5 mM phosphate buffer (pH 3.7) and 20 mM sodium dodecyl sulfate was used. The optimal separation of nine investigated analytes was achieved in 11 min, with limits of detection (S/N = 3) ranging from 0.11 to 0.61 µM. The linear ranges for all analytes were observed between 0.55 and 10.0 μM (R2 > 0.990). The developed approach was extended to the analysis of analytes in commercial wine and beer samples. The recoveries of the proposed method ranged from 98.8% to 115.6%.

scholarly journals A fast and efficient method for the study of caffeine levels in energy drinks using micellar electrokinetic chromatography (MEKC)

2012 ◽  
Vol 32 (2) ◽  
pp. 401-404 ◽  
Author(s):  
Cristiano Augusto Ballus ◽  
Adriana Dillenburg Meinhart ◽  
Carolina Schaper Bizzotto ◽  
José Teixeira Filho ◽  
Helena Teixeira Godoy
Keyword(s):  
Micellar Electrokinetic Chromatography ◽  
Brain Activity ◽  
Low Cost ◽  
Sodium Dodecyl ◽  
Energy Drinks ◽  
Electrokinetic Chromatography ◽  
The Central Nervous System ◽  
The Mean ◽  
High Doses

Energy drinks are becoming popular in Brazil and in the world due to their stimulant properties. Caffeine is present in energy drinks with the aim of stimulating the central nervous system and intensifying brain activity. On the other hand, the ingestion of high doses of caffeine can cause undesirable symptoms such as anxiety and tachycardia. Therefore, it is necessary to monitor the caffeine content added to energy drinks to guarantee that the levels in the final product are in accordance with the labeling and within the legislation limits. The goal of this work was to validate a fast, efficient, and low-cost method for the determination of caffeine in energy drinks by micellar electrokinetic chromatography (MEKC). A total of seven brands were analyzed, each in three lots. The electrolyte was prepared with 50 mmol.L-1 of sodium dodecyl sulfate (SDS) and 10 mmol.L-1 of sodium carbonate (pH 11.0). The mean concentration of caffeine ranged from 122.8 to 318.6 mg.L-1. None of the brands had caffeine levels above the maximum limit. Considering the interval of confidence (95%), 72% of the samples had less caffeine than the amount informed on the product label.

scholarly journals Determination of four naphthalenediols in cosmetic samples by sweeping-micellar electrokinetic chromatography and a comparison with HPLC

2021 ◽  
Author(s):  
Qian Wang ◽  
Xiaobin Li ◽  
Zhihan Zheng ◽  
Huitao Liu ◽  
Yuan Gao
Keyword(s):  
Micellar Electrokinetic Chromatography ◽  
Limit Of Detection ◽  
Low Cost ◽  
Hplc Method ◽  
National Standards ◽  
Sample Introduction ◽  
Electrokinetic Chromatography ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract A sweeping micellar electrokinetic chromatography (sweeping-MEKC) method was developed for the determination of 1,7-naphthalenediol, 2,3-naphthalenediol, 1,5-naphthalenediol and 2,7-naphthalenediol in cosmetics. Several parameters affecting sweeping-MEKC method were studied systematically and the separation conditions were optimized as 20 mM NaH2PO4–110 mM SDS and 40% (v/v) MeOH (pH 2.4), with −22 kV applied voltage and UV detection at 230 nm. The sample matrix is 60 mmol L−1 NaH2PO4 and sample introduction was performed at 3 psi for 6 s. Separation of the four naphthalenediols was completed in less than 17 min. Limit of detection (LOD) and limit of quantitation (LOQ) are 0.0045∼0.0094 μg mL−1 and 0.015∼0.031 μg mL−1. Linear relationship (r 2 > 0.999) is satisfactory at the range of 0.1–10 μg mL−1. The developed method has been successfully applied to the determination of the four naphthalenediols in real cosmetic samples, with recoveries in foundation, sun cream and lotion in the range of 92.3%∼106.8% and relative standard deviation (RSD) less than 4.15%. A HPLC method described in the National Standards of the People’s Republic of China was carried out for the comparison with the proposed method. The results showed that the proposed sweeping-MEKC method has the advantages of fast, low cost with comparative sensitivity.

LOW COST REAL TIME ROCKET TELEMETRY SYSTEM DESIGN

2019 ◽  
Author(s):  
Gabriel de Almeida Souza ◽  
Larissa Barbosa ◽  
Glênio Ramalho ◽  
Alexandre Zuquete Guarato
Keyword(s):  
System Design ◽  
Real Time ◽  
Low Cost ◽  
Telemetry System

Low-Cost High-Speed Techniques for Real-Time Simulation of Power Electronic Systems

2007 ◽  
Author(s):  
R. E. Crosbie ◽  
J. J. Zenor ◽  
R. Bednar ◽  
D. Word ◽  
N. G. Hingorani
Keyword(s):  
Real Time ◽  
High Speed ◽  
Low Cost ◽  
Electronic Systems ◽  
Power Electronic ◽  
Real Time Simulation ◽  
Time Simulation

Determination of Imipenem and Cilastatin in Medicinal Products by Micellar Electrokinetic Chromatography

2017 ◽  
Vol 13 (2) ◽  
pp. 158-166 ◽  
Author(s):  
Tyski Stefan ◽  
Gruba Ewa ◽  
Bukowska Bozena ◽  
Michalska Katarzyna ◽  
Karpiuk Izabela
Keyword(s):  
Micellar Electrokinetic Chromatography ◽  
Electrokinetic Chromatography ◽  
Medicinal Products

Quantitative Analysis of Duloxetine and 1-Naphthol by Capillary Micellar Electrokinetic Chromatography

2011 ◽  
Vol 7 (3) ◽  
pp. 184-193 ◽  
Author(s):  
Nathalie R. Wingert ◽  
Aline B. Barth ◽  
Patricia Gomes ◽  
Elfrides E. S. Shapoval ◽  
Martin Steppe
Keyword(s):  
Quantitative Analysis ◽  
Micellar Electrokinetic Chromatography ◽  
Electrokinetic Chromatography

scholarly journals Application of Deep Learning in Integrated Pest Management: A Real-Time System for Detection and Diagnosis of Oilseed Rape Pests

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Yong He ◽  
Hong Zeng ◽  
Yangyang Fan ◽  
Shuaisheng Ji ◽  
Jianjian Wu
Keyword(s):  
Deep Learning ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Real Time ◽  
Oilseed Rape ◽  
Data Augmentation ◽  
Low Cost ◽  
Response Speed ◽  
Original Model ◽  
Real Time System

In this paper, we proposed an approach to detect oilseed rape pests based on deep learning, which improves the mean average precision (mAP) to 77.14%; the result increased by 9.7% with the original model. We adopt this model to mobile platform to let every farmer able to use this program, which will diagnose pests in real time and provide suggestions on pest controlling. We designed an oilseed rape pest imaging database with 12 typical oilseed rape pests and compared the performance of five models, SSD w/Inception is chosen as the optimal model. Moreover, for the purpose of the high mAP, we have used data augmentation (DA) and added a dropout layer. The experiments are performed on the Android application we developed, and the result shows that our approach surpasses the original model obviously and is helpful for integrated pest management. This application has improved environmental adaptability, response speed, and accuracy by contrast with the past works and has the advantage of low cost and simple operation, which are suitable for the pest monitoring mission of drones and Internet of Things (IoT).

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