Simple and low-cost sensor based on activated biochar for the stripping voltammetric detection of caffeic acid

2020 ◽  
Vol 159 ◽  
pp. 105380 ◽  
Author(s):  
Cristiane Kalinke ◽  
Ana P. Zanicoski-Moscardi ◽  
Paulo R. de Oliveira ◽  
Antonio S. Mangrich ◽  
Luiz H. Marcolino-Junior ◽  
...  
Keyword(s):  
Caffeic Acid ◽  
Low Cost ◽  
Activated Biochar ◽  
Voltammetric Detection

Voltammetric detection of 3,4-methylenedioxymethamphetamine (mdma) in saliva in low cost systems

2020 ◽  
Vol 20 ◽  
pp. 100268
Author(s):  
Érica Naomi Oiye ◽  
Juliana Midori Toia Katayama ◽  
Maria Fernanda Muzetti Ribeiro ◽  
Leandro Oka Duarte ◽  
Rodrigo de Castro Baker Botelho ◽  
...  
Keyword(s):  
Low Cost ◽  
Voltammetric Detection

scholarly journals Spectrophotometric and Smartphone-Assisted Determination of Phenolic Compounds Using Crude Eggplant Extract

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4407 ◽  
Author(s):  
M.A. Morosanova ◽  
A.S. Bashkatova ◽  
E.I. Morosanova
Keyword(s):  
Phenolic Compounds ◽  
Chlorogenic Acid ◽  
Caffeic Acid ◽  
Polyphenol Oxidase ◽  
Oxidase Activity ◽  
Biological Fluids ◽  
Low Cost ◽  
Analytical Signal ◽  
Polyphenol Oxidase Activity

In order to develop a simple, reliable and low cost enzymatic method for the determination of phenolic compounds we studied polyphenol oxidase activity of crude eggplant (S. melongena) extract using 13 phenolic compounds. Catechol, caffeic and chlorogenic acids, and L-DOPA have been rapidly oxidized with the formation of colored products. Monophenolic compounds have been oxidized at a much slower speed. Ferulic acid, quercetin, rutin, and dihydroquercetin have been found to inhibit polyphenol oxidase activity of crude eggplant extract. The influence of pH, temperature, crude eggplant extract amount, and 3-methyl-2-benzothiazolinone hydrazone (MBTH) concentration on the oxidation of catechol, caffeic acid, chlorogenic acid, and L-DOPA has been investigated spectrophotometrically. Michaelis constants values decrease by a factor of 2 to 3 in the presence of MBTH. Spectrophotometric (cuvette and microplate variants) and smartphone-assisted procedures for phenolic compounds determination have been proposed. Average saturation values (HSV color model) of the images of the microplate wells have been chosen as the analytical signal for smartphone-assisted procedure. LOD values for catechol, caffeic acid, chlorogenic acid, and L-DOPA equaled 5.1, 6.3, 5.8 and 30.0 µM (cuvette procedure), 12.2, 13.2, 13.2 and 80.4 µM (microplate procedure), and 23.5, 26.4, 20.8 and 120.6 µM (smartphone procedure). All the variants have been successfully applied for fast (4-5 min) and simple TPC determination in plant derived products and L-DOPA determination in model biological fluids. The values found with smartphone procedure are in good agreement with both spectrophotometric procedures values and reference values. Using crude eggplant extract- mediated reactions combined with smartphone camera detection has allowed creating low-cost, reliable and environmentally friendly analytical method for the determination of phenolic compounds.

scholarly journals Equilibrium and Kinetic Studies for The Adsorptive Removal of Lead (II) Ions from Aqueous Solution Using Activated Plantain Peel Biochar

2020 ◽  
Vol 4 (1) ◽  
pp. 9-16
Author(s):  
FS Nworie ◽  
EC Oroke ◽  
II Ikelle ◽  
JS Nworu
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
Metal Ion ◽  
Low Cost ◽  
Kinetic Studies ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Intraparticle Diffusion Model ◽  
Activated Biochar ◽  
Bet Analysis

AbstractStudies on the adsorption of Pb(II) on plantain peels biochar (PPB) was conducted. The carbonized and activated, biochar was characterized using Braunauer-Emmett-Teller (BET) surface area and x-ray diffraction crystallography (XRD). BET analysis of the PPB indicated that the pore size (cc/g) and pore surface area (m2/g) was 8.79 and 16.69 respectively. Result of the XRD evaluated through Debye-Scherrer equation, showed a nanostructure with crystallite size of 14.56 nm. Effects of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Results showed that the adsorption of lead from aqueous solution increased with an increase in pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Weber and Morris intraparticle diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies indicated the potential of plantain peel biochar as an effective, efficient and low cost adsorbent for remediating lead (II) ions contaminated environment.

scholarly journals A Low Cost Fe3O4–Activated Biochar Electrode Sensor by Resource Utilization of Excess Sludge for Detecting Tetrabromobisphenol A

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 115
Author(s):  
Suxing Luo ◽  
Meizhi Yang ◽  
Yuanhui Wu ◽  
Jiang Li ◽  
Jun Qin ◽  
...  
Keyword(s):  
Electrochemical Sensors ◽  
Low Cost ◽  
Active Surface ◽  
Charge Transfer Resistance ◽  
Tetrabromobisphenol A ◽  
Active Surface Area ◽  
Excess Sludge ◽  
Transfer Resistance ◽  
Activated Biochar ◽  
Bet Analysis

Owing to its ubiquity in natural water systems and the high toxicity of its accumulation in the human body, it is essential to develop simple and low-cost electrochemical sensors for the determination of 3,3′,5,5′-tetrabromobisphenol A (TBBPA). In this work, Fe3O4–activated biochar, which is based on excess sludge, was prepared and characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and BET analysis to analyze its basic features. Subsequently, it was used to fabricate an electrochemical sensor for the detection of TBBPA. The electrochemical test results revealed that the Fe3O4–activated biochar film exhibited a larger active surface area, a lower charge transfer resistance and a higher accumulation efficiency toward TBBPA. Consequently, the peak current of TBBPA was significantly enhanced on the surface of the Fe3O4–activated biochar. The TBBPA sensing platform developed using the Fe3O4–activated biochar composite film, with relatively a lower detection limit (3.2 nM) and a wider linear range (5–1000 nM), was successfully utilized to determine TBBPA levels in water samples. In summary, the effective application of Fe3O4–activated biochar provided eco-friendly and sustainable materials for the development of a desirable high-sensitivity sensor for TBBPA detection.

scholarly journals Facile preparation of 3D GO with caffeic acid for efficient adsorption of norfloxacin and ketoprofen

2020 ◽  
Vol 81 (7) ◽  
pp. 1461-1470
Author(s):  
Ying Lu ◽  
Youlin Li ◽  
Yi Gao ◽  
BoXuan Ai ◽  
Wei Gao ◽  
...  
Keyword(s):  
Caffeic Acid ◽  
Organic Compounds ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Contaminated Water ◽  
Fast Diffusion ◽  
Green Method ◽  
3D Graphene ◽  
High Sorption

Abstract In this paper, a simple and green method was developed to fabricate a three-dimensional (3D) graphene-based material with the assistance of caffeic acid (CA). The prepared 3D graphene displayed fast and high sorption for norfloxacin (NOR) and ketoprofen (KP). Their adsorption equilibrium was achieved within 12 h for NOR and KP, which was attributed to their fast diffusion in the porous structure of the 3D graphene. The maximum adsorbed amount of this adsorbent was 220.99 mg/g for NOR and 125.37 mg/g for KP according to the Langmuir model at pH 6.6, 298 K. In the competitive adsorption of six pharmaceuticals, the organic compounds in the form of cations are preferentially adsorbed on the adsorbent. The co-existing organic compounds in the actual wastewater do not seriously inhibit the adsorption of NOR and KP. This study provides the theoretical basis for the facile and low-cost preparation of high-performance 3D graphene adsorbents. The results of this study demonstrate the potential utility of 3D graphene as a very effective adsorbent for pharmaceuticals removal from contaminated water.

scholarly journals Low-Cost Biochar Adsorbents for Water Purification Including Microplastics Removal

2020 ◽  
Vol 10 (3) ◽  
pp. 788 ◽  
Author(s):  
Virpi Siipola ◽  
Stephan Pflugmacher ◽  
Henrik Romar ◽  
Laura Wendling ◽  
Pertti Koukkari
Keyword(s):  
Water Purification ◽  
Low Cost ◽  
Aqueous Media ◽  
Chemical Species ◽  
Exchange Capacity ◽  
Economic Feasibility ◽  
Surface Areas ◽  
Activated Biochar ◽  
Spruce Bark ◽  
Test Parameters

The applicability of steam activated pine and spruce bark biochar for storm water and wastewater purification has been investigated. Biochar samples produced from the bark of scots pine (Pinus sylvestrus) and spruce (Picea spp.) by conventional slow pyrolysis at 475 °C were steam activated at 800 °C. Steam activation was selected as a relatively inexpensive method for creating porous biochar adsorbents from the bark-containing sidestreams of the wood refining industry. A suite of standard analytical procedures were carried out to quantify the performance of the activated biochar in removing both cations and residual organics from aqueous media. Phenol and microplastics retention and cation exchange capacity were employed as key test parameters. Despite relatively low surface areas (200–600 m2/g), the steam-activated biochars were highly suitable adsorbents for the chemical species tested as well as for microplastics removal. The results indicate that ultra-high porosities are not necessary for satisfactory water purification, supporting the economic feasibility of bio-based adsorbent production.

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