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Yanggu, South Korea

Abdel-Ghani N.T.,Cairo University | Rizk M.S.,Cairo University | Mostafa M.,Forensic Chemistry Laboratory
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

Simple, rapid, sensitive, precise and accurate spectrophotometeric methods for the determination of ephedrine hydrochloride (E-HCl) and bromhexine hydrochloride (Br-HCl) in bulk samples, dosage form and in spiked urine samples were investigated. The methods are based on the formation of a yellow colored ion-associates due to the interaction between the examined drugs with picric acid (PA), chlorophyllin coppered trisodium salt (CLPH), alizarin red (AR) and ammonium reineckate (Rk) reagents. A buffer solution had been used and the extraction was carried out using organic solvent, the ion associates exhibit absorption maxima at 410, 410, 430 and 530 nm of (Br-HCl)with PA, CLPH, AR and Rk respectively; 410, 410, 435 and 530 of (E-HCl) with PA, CLPH, AR and Rk respectively. (E-HCl) and (Br-HCl) could be determined up to 13, 121, 120 and 160; 25, 200, 92 and 206 μg mL-1, using PA, CLPH, AR and Rk respectively. The optimum reaction conditions for quantitative analysis were investigated. In addition, the molar absorptivity, Sandell sensitivity were determined for the investigated drug. The correlation coefficient was ≥0.995 (n = 6) with a relative standard deviation (RSD) ≤1.15 for five selected concentrations of the reagents. Therefore the concentration of Br-HCl and E-HCl drugs in their pharmaceutical formulations and spiked urine samples had been determined successfully. © 2013 Elsevier B.V. All rights reserved. Source


Shahat A.,Suez Canal University | Ali Mohammad E.A.,Forensic Chemistry Laboratory | El Shahat M.F.,Ain Shams University
Sensors and Actuators, B: Chemical | Year: 2015

Abstract Simple, rapid, sensitive, precise and accurate spectrophotometeric methods for detection and removal of ultra-traces of some toxic metal ions such as Cu(II), Pb(II), Hg(II) and Cd(II) in water and in biological samples have been developed. The procedure depends on a single-step detection and removal for metal ions based on dithizone (Dz) anchored on mesoporous TiO2 with rapid colorimetric response and high selectivity for the first time. The developed sensor was utilized for the detection of ultra-traces of some toxic metal ions with the naked eye. The new sensor displays high sensitivity and selectivity of a wide range of detectable metals analytes up to 10-9 mol dm-3 in solution. The proposed method was applied to the determination of the examined metal ions in post-mortem biological samples. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision. © 2015 Elsevier B.V. Source


Atta N.F.,Cairo University | Galal A.,Cairo University | Ali S.M.,Cairo University | Hassan S.H.,Forensic Chemistry Laboratory
Ionics | Year: 2015

Poly(3,4-ethylenedioxythiophene) (PEDOT) modified with ferrocene carboxylic acid (FC1), ferrocene (FC2), and cobaltocene (CC) is introduced as a sensor electrode. FC or CC was “sandwiched” between two layers of PEDOT in the presence of sodium dodecyl sulfate (PEDOT/mediator/PEDOT…SDS). The composite electrodes were evaluated for the electrocatalytic oxidation of dopamine (DA). The FC1 mediator showed the highest rate for electron transfer and enhanced electrocatalytic activity. This is due to the inclusion of the ferrocenium ion and the polar substituted –COOH group in the matrix which increases the electronic conduction of the film. SDS enhanced the preconcentration/accumulation of DA ions at the surface that resulted in enhanced detection. Detection limit in human urine was 0.069 μmol L−1 in the linear dynamic range of 6–300 μmol L−1, with satisfying recovery results. The PEDOT/FC1/PEDOT…SDS composite was used for simultaneous determination of dopamine in the presence of ascorbic acid (AA) and uric acid (UA). © 2015, Springer-Verlag Berlin Heidelberg. Source


Ryu S.-J.,Seoul National University | Ryu S.-J.,Forensic Chemistry Laboratory | Arifin E.,Korea University | Ha S.-W.,Seoul National University | Lee J.-K.,Seoul National University
Bulletin of the Korean Chemical Society | Year: 2015

Immensely sensitive, accurate, and simple on-site colorimetric sensor has been developed for the quantitative detection of the sulfide ion in human blood plasma. The colorimetric sensor consists of lead-ion-modified silica-gel powders placed in a glass tube. The powder color changes upon reaction with sulfide ions in blood plasma. It is capable of easily detecting toxic sulfide ion by using a glass tube with an inner diameter of 3 mm. By employing the type of colorimetric sensor to a blood sample, it is possible to detect the sulfide ion with a concentration limit of 0.1 ppm and excellent reproducibility, thus making it superior to conventional analysis methods that need multiple preparation processes and various sophisticated instruments. Since the sensor reported here isinsensitive to environmental conditions such as temperature or humidity, and isfeatured by simplicity, fast response, high sensitivity, and easily understandable results based on absolute affirmative/negative response, it is expected to be effectively used for on-site applications such as detecting poisonous ions in blood samples. © 2015 Korean Chemical Society, Seoul & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Ryu S.-J.,Seoul National University | Ryu S.-J.,Forensic Chemistry Laboratory | Arifin E.,Korea University | Ha S.-W.,Seoul National University | Lee J.-K.,Seoul National University
Bulletin of the Korean Chemical Society | Year: 2015

A highly sensitive on-site colorimetric forensic sensor has been developed for the quantitative detection of hydrogen sulfide and ammonia gases. The sensor consists of metal-ion-modified silica-gel powders placed in a glass tube. The powder color changes upon reaction with toxic hydrogen sulfide and ammonia gases. It is capable of easily detecting toxic gases in the concentration range between 100 ppm, which is considered as immediately dangerous to life and health, and 3000 ppm, which may cause death, by using a glass tube with an inner diameter of 3 mm. As the sensor reported here is insensitive to environmental conditions such as temperature or humidity, and is featured by simplicity, fast response, high sensitivity, and easily understandable results based on absolute affirmative/negative response, it is expected to be effectively used for on-site applications such as testing the existence of toxic gases in confined working and industrial spaces. © 2015 Korean Chemical Society, Seoul & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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