Laser-induced breakdown spectroscopy (LIBS) is a laser based method for the qualitative and quantitative analysis of chemical elements. It could be used for the analysis of rubber blends in the mixing room. The quality of rubber products depends on the correct blending of the mixing components. For example short mixing times can lead to an inhomogeneous dispersion of these components. With LIBS it is possible to detect zinc in rubber blends by using a Nd:YAG laser with a wavelength of 1064 nm and a pulse energy of 100 mJ. The intensity of the spectral lines is strongly affected by the setup parameters like the focal position. The use of calibration samples allows creating a calibration curve. Based on line scans, the zinc dispersion in these rubber blends can be analyzed. Variations in the homogeneity of the zinc caused by short mixing times or different rotation speed of the mixer can be detected by the evaluation of the intensity profile along these line scans.