This publication presents a comprehensive method for assessing the homogeneity of the composition of a large batch of polymer materials, with a mass of 1.5 tons, consisting of 60 transport packages, using the example of rubber granulate from recycled car tires. The presented method combines statistical analysis tools used to determine the samples number to be taken from the batch and the pyrolytic thermal desorption technique coupled with gas chromatography-mass spectrometry (Py/TD-GC-MS), used for material identification. Directions for improving the method for the quantitative identification of batch components are also indicated. The developed method can be applied to assess the purity of batches of recycled rubber granulate used in the construction of sports field surfaces and to determine the content of substances harmful to the environment and human health, such as polycyclic aromatic hydrocarbons. The direction for improving the developed spot-check control method using an alternative approach is to supplement it with a quantitative assessment of batch parameters in relation to the threshold values, such as tolerance limits.