By the example of chemical elements in the form of elementary substance it was shown that the total content of elemental impurities can be considered as an objective and generalized index of the purity of individual matter. Impurity composition of the volatile compounds evaluated on the experimental results was presented in the form of two information files: (i) the content of chemical elements for low-volatile impurities, and (ii) the content of impurities with specified molecular structure (taking, into account that the volatility of impurity and base is comparable). A unified approach to the presentation of the impurity composition data of volatile compounds, which considers the elemental composition of both groups of impurities and allows estimating of the total content of elemental impurities in compound, has been developed. In the framework of this approach the average total impurity content of the high-purity volatile chloride samples, which are available at the Collection Exhibition of Special Purity Substances, were evaluated.