Реферат: The paper considers some aspects of classical methods of determination of carbon and hydrogen with gravimetric termination of analysis and method of determination of carbon, hydrogen and nitrogen on Carlo Erba elemental automatic analyzer. For this purpose we used the statistics of analytical archives, i. e., the previously accumulated results of laboratory analyses of standard compounds and various organic compounds with known contents of carbon, hydrogen and nitrogen. The sample determinations have been made, each including 50 parallel determinations of standard compounds (for classical methods, of acetanilide, sulfanil acid, tris(pentafluorophenyl)carbinol; for automatic, of p-nitroanilyne and acetanilide) and 25 various organic compounds of known structure (by two parallel determinations). A procedure for processing these results has been suggested and metrological characteristics: confidence interval, correctness, and agreement between classical and automatic methods have been determined. The results obtained show agreement between the standard and nonstandard methods for carbon and hydrogen. Standard deviation slightly exceeds 0.2. The results for carbon also show an agreement between classical and automatic methods. On hydrogen determination, reproducibility of automatic methods is better, standard deviation is less by an order of magnitude. In classical variant of the method, increased standard deviation for hydrogen has been observed in case of this (pentafluorophenyl)carbinol and sulfanil acid, which may be explained by influence of such elements as fluorine and sulfur. The range of concentrations determined being from 30 to 85 % for carbon, from 1 to 15 % for hydrogen and from 1 to 40 % for nitrogen does not influence the value of error both in classical and automatic methods. The procedure for processing the results may be recommended for methods of determination of other elements.

Библиографическая ссылка: Tikhova V.D. , Morjakina I.M. , Fadejeva V.P.
EVALUATION OF METROLOGICAL CHARACTERISTICS OF METHODS OF CLASSICAL AND AUTOMATIC-DETERMINATION OF CARBON, HYDROGEN AND NITROGEN IN ORGANIC-COMPOUNDS
SIBIRSKII KHIMICHESKII ZHURNAL. 1991. N4. P.50-54. WOS

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Web of science

WOS:A1991HE43300009