Development of Techniques of Generation of Gaseous Standard Mixtures

Abstract

Various reference materials are increasingly used in analytical work. This is directly related to the assessment and quality control of results of measurements in order to make them a reliable source of analytical information. Reference materials are an indispensable tool in the development and validation of new analytical procedures. They also are often used in interlaboratory studies. The use of reference materials allows maintaining traceability. More and more reference materials containing analytes in solid and liquid matrices are becoming available. However, gaseous reference materials are much less available. This is because of the lack of stability with this type of reference materials. Consequently, not all techniques of the generation of gaseous standard mixtures can be used to prepare appropriate matrix-free gaseous reference materials. This article discusses the following topics: (1) classification of known techniques of generation of gaseous standard mixtures; and (2) review of most commonly used techniques, including schematic diagrams of the apparatus. The article also includes the information on a new approach to the problem of generation of gaseous standard mixtures whereby the analyte is generated in the process of thermal decomposition of suitable immobilized compounds formed by chemical modification of an appropriate solid support.