CERTIFICATION OF VL-2, A VENEZUELAN LATERITIC MATERIAL AS A STANDARD REFERENCE MATERIAL

A description of the preparation and certification of a second lateritic material (high in SiO2 content) from Venezuela is presented. The certification was based on the results from an intercomparison study of fourteen international laboratories after the bottled samples were considered to be homogeneous. The proposed values (the median) for the main constituents are: Al2O3: 27.03%; Fe2O3: 32.28%; SiO2: 20.24%; TiO2: 3.00% and LOI: 16.26%. The following statistical parameters are also given for each component: the mean, the range of values, the 95% confidence limits of the mean, the geometric mean, the variance, the standard deviation; the coefficient of variation, the standard error of the mean, the standard error of the standard deviation, the coefficient of skewness, the coefficient of kurtosis, the dominant cluster mode, the Gastwirth median, the median and its 95% confidence limits. Finally, the frequency distributions of the results for the various components are shown, which were discriminated by their analytical method.