THEORETICAL FOUNDATIONS AND EXPERIENCE OF IMPLEMENTING THE VALIDATION PROCEDURE OF THE QUANTITATIVE CHEMICAL ANALYSIS METHOD IN A TESTING LABORATORY
Currently, chemistry and petrochemistry are one of the most progressive and rapidly developing industries of the world industry, the activity of which has a negative impact on the environment: harmful components accumulate in the air, are discharged into water bodies, and remain in the soil. Therefore, ensuring environmental safety has become an urgent task of modern society. One way to solve this problem is to constantly monitor the state of natural objects and forecast the development of the situation based on the results of environmental monitoring carried out by specialized testing laboratories. In order to carry out their activities in the relevant field, the latter must undergo the accreditation procedure and confirm their qualifications, i.e. the ability to conduct analytical determinations with accurate, correct and reliable results. For this purpose, in the analytical laboratory it is necessary to introduce a verification procedure for the certified methodology used, consisting in evaluating its performance (repeatability, precision, accuracy, accuracy indicator, etc.) in a specific laboratory and establishing their compliance with the specified requirements. This article contains the results of verification of the method for chromatographic determination of benzene in atmospheric air using standard gas mixtures of benzene with known content as standard samples. It was established that the experimentally obtained intralaboratory indicators of reproducibility and accuracy do not exceed normalized values, therefore, the laboratory is authorized to use this technique and is able to guarantee the appropriate quality of the results of its measurements. Along with this, indicators of intralaboratory repeatability and correctness are determined that are not standardized by the methodology.