scholarly journals Activated Carbon from Fly Ash of Heavy Fuel Oil: Characterization and its Utilization for Removal and Determination of Chlorophenonls in Water

2017 ◽  
Vol 14 (3) ◽  
pp. 1103-1116 ◽  
Author(s):  
A. Abu-Rizaiza ◽  
M.W. Kadi ◽  
M.S. El-Shahawi

ABSTRACT: Activated carbons (AC) prepared from volatile fly ash (FA) of heavy fuel oil via gasification with combined steam - CO2 was characterized and used as a low- cost adsorbent for removal of chlorophenols (CPs) e.g. 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), and 2,4,6- tetra chlorphenol (TCP) in water. At pH< 2.0, maximum CPs uptake was achieved and the average half-life time (t1/2) of the equilibrium adsorption of CPs was in the range 0.80 ± 0.01- 1.1 ± 0.04 h. Data suggested use of AC in packed column for separation and determination of various concentrations (0.5-100 µgL-1) of CPs in water (0.5-1.0 L). Complete extraction and recovery (97.4 + 2.9 %, n=5) of CPs were achieved at 2 mL min-1 flow rate. Analysis of CPs spiked onto tap- and seawater were also analyzed by AC packed column and the results were compared with the standard HPLC method at 95% confidence (P-0.05, n=5). The experimental student t test (texp 1.81-1.93) and F (Fexp 1.21-5.76) values were lower than the tabulated t (tcrit. = 2.78) and F (6.38), respectively. AC packed column provides remarkable selectivity, reproducibility, and cost-effectiveness towards removal and/ or determination of CPs. AC adsorbent may serve positively in point-of-care use.

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 189
Author(s):  
Susana Campuzano ◽  
Paloma Yáñez-Sedeño ◽  
José Manuel Pingarrón

The multifaceted key roles of cytokines in immunity and inflammatory processes have led to a high clinical interest for the determination of these biomolecules to be used as a tool in the diagnosis, prognosis, monitoring and treatment of several diseases of great current relevance (autoimmune, neurodegenerative, cardiac, viral and cancer diseases, hypercholesterolemia and diabetes). Therefore, the rapid and accurate determination of cytokine biomarkers in body fluids, cells and tissues has attracted considerable attention. However, many currently available techniques used for this purpose, although sensitive and selective, require expensive equipment and advanced human skills and do not meet the demands of today’s clinic in terms of test time, simplicity and point-of-care applicability. In the course of ongoing pursuit of new analytical methodologies, electrochemical biosensing is steadily gaining ground as a strategy suitable to develop simple, low-cost methods, with the ability for multiplexed and multiomics determinations in a short time and requiring a small amount of sample. This review article puts forward electrochemical biosensing methods reported in the last five years for the determination of cytokines, summarizes recent developments and trends through a comprehensive discussion of selected strategies, and highlights the challenges to solve in this field. Considering the key role demonstrated in the last years by different materials (with nano or micrometric size and with or without magnetic properties), in the design of analytical performance-enhanced electrochemical biosensing strategies, special attention is paid to the methods exploiting these approaches.


2019 ◽  
Vol 3 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Bianca Marco ◽  
Ana Kogawa ◽  
Hérida Salgado

Cefadroxil, an oral antimicrobial, presents few techniques optimized for the reduction of solvents and toxic residues and/or non-use of them. So, a quantitative, new and miniaturized method for determination of cefadroxil monohydrate in capsules has been developed and validated by spectrophotometric method in the visible region according to the international guidelines. The analyzes were performed using microplates containing 96 wells, 1 % of phenolphthalein and sodium hydroxide 0.1 M as reagent at 552 nm. The method was (i) linear in the range of 15-115 µg mL-1, (ii) selective when comparing standard, sample, adjuvants and color reagent, (iii) precise with deviations below 4 %, (iv) accurate when comparing the proposed method with the HPLC method, (v) robusts by making small and deliberate modifications to the method, (vi) besides being fast, low cost, eco-friendly and generates minimal amount of waste. The method can be applied to the routine quality control of cefadroxil monohydrate in capsules and an effective and accessible alternative that contemplates the concepts of current and sustainable green analytical chemistry.


2016 ◽  
Vol 4 (2) ◽  
pp. 123-143 ◽  
Author(s):  
Mohammed A. Al-Osta ◽  
Mirza G. Baig ◽  
Muhammad H. Al-Malack ◽  
Omar S. Baghabra Al-Amoudi

1977 ◽  
Vol 27 (6) ◽  
pp. 1614-1615
Author(s):  
M. E. Lapinskaya ◽  
E. S. Shitt
Keyword(s):  
Fly Ash ◽  
Fuel Oil ◽  

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 869 ◽  
Author(s):  
Raquel Pruna ◽  
Francisco Palacio ◽  
Isabel Fuentes ◽  
Clara Viñas ◽  
Francesc Teixidor ◽  
...  

A novel transparent and nanostructured ion-sensitive electrode based on indium tin oxide (ITO) coated with cobaltbis(dicarbollide)-doped poly(pyrrole) (PPy) is presented in this work. This metallacarborane-doped PPy was used as conducting polymer due to its high stability and chemical resistance. The ion-sensitive electrode was coupled to a miniaturized and low-cost potentiostat, in a final autonomous kit for potentiometric determination of pH. Qualitative calibration of the system revealed Nernstian behavior, resulting promising for novel point-of-care biomedical applications.


Author(s):  
Qian Wang ◽  
Xiaobin Li ◽  
Zhihan Zheng ◽  
Huitao Liu ◽  
Yuan Gao

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.


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