start-ver=1.4 cd-journal=joma no-vol=24 cd-vols= no-issue=4 article-no= start-page=493 end-page=498 dt-received= dt-revised= dt-accepted= dt-pub-year=2008 dt-pub=20080410 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Electrochemical Analysis of Chloramphenicol Using Boron-doped Diamond Electrode Applied to a Flow-Injection System en-subtitle= kn-subtitle= en-abstract= kn-abstract=

The electrochemical properties of chloramphenicol at a boron-doped diamond thin-film (BDD) electrode were studied using cyclic voltammetry. The highest current response of chloramphenicol was obtained with phosphate buffer, pH 6 (0.1 M) in 1% ethanol. The relationship between the concentration of chloramphenicol and the current response was linear over the range of 0.1 - 10 mM (R-2 = 0.9990). The amount of chloramphenicol was analyzed by flow-injection analysis. A thin-layer flow cell equipped with a BDD electrode was used as an amperometric detector, and experiments were carried out at -0.7 V (vs. Ag/AgCl). The linear relationship between the current response and the concentration of chloramphenicol in the range of 0.1 - 50 mu M (R-2 = 0.9948) and the limit of detection of 0.03 mu M (S/N = 3) were obtained. This method has been successfully applied to the determination of chloramphenicol in sterile eye drops and milk sample by the standard addition method. The average recoveries of chloramphenicol in eye drops were 98.0%, and the average recoveries of chloramphenicol from spiked milk were 93.9 - 103%.

en-copyright= kn-copyright= en-aut-name=ChuanuwatanakulSuchada en-aut-sei=Chuanuwatanakul en-aut-mei=Suchada kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ChailapakulOrawon en-aut-sei=Chailapakul en-aut-mei=Orawon kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MotomizuShoji en-aut-sei=Motomizu en-aut-mei=Shoji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Department of Chemistry, Faculty of Science, Chulalongkorn University affil-num=2 en-affil= kn-affil=Department of Chemistry, Faculty of Science, Chulalongkorn University affil-num=3 en-affil= kn-affil=Department of Chemistry, Faculty of Science, Okayama University en-keyword=THIN-FILM ELECTRODE kn-keyword=THIN-FILM ELECTRODE en-keyword=TANDEM MASS-SPECTROMETRY kn-keyword=TANDEM MASS-SPECTROMETRY en-keyword=CAPILLARY-ZONE-ELECTROPHORESIS kn-keyword=CAPILLARY-ZONE-ELECTROPHORESIS en-keyword=LIQUID-CHROMATOGRAPHY kn-keyword=LIQUID-CHROMATOGRAPHY en-keyword=AMPEROMETRIC DETECTION kn-keyword=AMPEROMETRIC DETECTION en-keyword=PHOTOCHEMICAL-REACTION kn-keyword=PHOTOCHEMICAL-REACTION en-keyword=OXIDATION kn-keyword=OXIDATION en-keyword=PRODUCTS kn-keyword=PRODUCTS en-keyword=RESIDUES kn-keyword=RESIDUES en-keyword=CARBON kn-keyword=CARBON END start-ver=1.4 cd-journal=joma no-vol=24 cd-vols= no-issue=4 article-no= start-page=505 end-page=508 dt-received= dt-revised= dt-accepted= dt-pub-year=2008 dt-pub=20080410 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Spectrophotometric Determination of 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide Hydrochloride by Flow Injection Analysis en-subtitle= kn-subtitle= en-abstract= kn-abstract=1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC?HCl) is a very useful agent to form amide bonds (peptide bonds) in an aqueous medium. A simple and fast detection system was developed using the reaction with pyridine and ethylenediamine in acidic aqueous solution and spectrophotometric flow injection analysis. The absorbances were measured at 400 nm and the reaction was accelerated at 40?C. The calibration graph showed good linearity from 0 to 10% of EDC?HCl solutions: the regression equation was y = 3.15 × 104x (y, peak area; x, % concentration of EDC?HCl). The RSD was under 1.0%. Sample throughput was 15 h?1. This method was applied to monitoring the EDC?HCl concentration that remained after the anhydration of phthalic acid in water, esterification of acetic acid in methanol or dehydration condensation of malonic acid and ethylenediamine in water. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=KunihikoSeno kn-aut-sei=Kunihiko kn-aut-mei=Seno aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=KazukiMatsumura kn-aut-sei=Kazuki kn-aut-mei=Matsumura aut-affil-num=2 ORCID= en-aut-name=OshimaMitsuko en-aut-sei=Oshima en-aut-mei=Mitsuko kn-aut-name=大島光子 kn-aut-sei=大島 kn-aut-mei=光子 aut-affil-num=3 ORCID= en-aut-name=MotomizuShoji en-aut-sei=Motomizu en-aut-mei=Shoji kn-aut-name=本水昌二 kn-aut-sei=本水 kn-aut-mei=昌二 aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=岡山大学 affil-num=2 en-affil= kn-affil=岡山大学 affil-num=3 en-affil= kn-affil=岡山大学 affil-num=4 en-affil= kn-affil=岡山大学 END