The capabilities of a two-jet arc plasma for solving analytical tasks that are difficult to do by other spectral methods have been shown. We have proposed procedures, both direct and after heat treatment of the sample, for the atomic emission spectroscopic analysis of brown coal and protein complexes of low weight using graphite-powder-based reference samples and simple sample preparation (dilution of the sample with spectroscopic buffer). Owing to the ability of the ATOM program to record the spectra of each base exposure, a method for detecting inclusion elements in diamond particles weighing less than 1 mg has been proposed. The advantages of this method over other spectral methods in solving specific analytical tasks are discussed. All the techniques described in the work have been performed using a new design plasmatron developed by VMK-Optoelektronika.