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Tumskaia A. V., Kosyreva I. V. Express determination of cephalexin. Izvestiya of Saratov University. Chemistry. Biology. Ecology, 2021, vol. 21, iss. 3, pp. 260-266. DOI:

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Express determination of cephalexin

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RAR научная статья

Test means based on immobilized Fehling’s reagent for the determination of cephalexin have been obtained. Methods for visual and colorimetric assessment of antibiotic concentration using a smartphone camera have been developed. The optimal conditions for the indicator reaction have been selected with varying heating time and temperature. For a visual semi-quantitative assessment of the content of cephalexin, a color scale has been obtained. The metrological characteristics of the test method have been determined: the range of the determined contents is 0.5–16 mg/ml, the unreliability interval is 0.1–0.4 mg/ml, and the detection limit is 0.4 mg / ml. For the colorimetric assessment of the concentration of cephalexin, a linear dependence of the intensity of the Blue channel on the logarithm of the concentration of cephalexin (у = –96x + 144, r 2 = 0.99) has been constructed, and linear dependences of the area (у = –36986x + 62458, r 2 = 0.96) and perimeter (у = –270x + 786, r 2 = 0.93) from the logarithm of the concentration of cephalexin have been obtained. The range of the determined contents was 0.1–16 mg/ml, the lower limit was 0.1 mg / ml. The verification of the correctness of the developed test methods was carried out by the «introduced-found» method (Sr  0.13).

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