Acta Medica Okayama 24 4 2008 Electrochemical Analysis of Chloramphenicol Using Boron-doped Diamond Electrode Applied to a Flow-Injection System 493 498 EN Suchada Chuanuwatanakul Orawon Chailapakul Shoji Motomizu <p>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%.</p> No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 24 4 2008 Spectrophotometric Determination of 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide Hydrochloride by Flow Injection Analysis 505 508 EN Mitsuko Oshima Shoji Motomizu 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. No potential conflict of interest relevant to this article was reported.