METHODS AND OBJECTS OF CHEMICAL ANALYSIS ISSN title: "Metody i obʺekty himičeskogo analiza" An international journal devoted to all aspects of Analytical chemistry ISSN 2413-6166 (Online), ISSN 1991-0290 (Print)
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Chugunov B.M., Kovalchuk T.N., Antonovich V.P.

Cryoscopy method for the determining the content of the major substance as a means of certification of reference materials of pesticides

 For the certification of reference materials of pesticides it has been proposed to determine the content of the major substance through the cryoscopy method using standard additives – the artificial impurities. On the example of 2,4-dichlorophenoxyacetic acid it was shown that this technique allows to reach high precision results (relative error is 0,1–0,2%), which are in good agreement with data of titrimetric and chromatographic analysis. The advantages of the proposed method are simplicity and availability of equipment, the opportunity to work with small quantities of substances, precision, comparable to accuracy of titrimetry.

Keywords: reference materials, cryoscopy, melting point depression, molar fraction of impurities