Conditions for the analysis of liquid samples on a MFS-8 spectrometer upgraded with a MAES photodiode array by arc atomic emission spectrometry with dry residue technique are specified. It is shown that optimization of the electrode shape along with the method of calculating the intensity of the spectral line and time of the base exposure leads to the expansion of the operating range of calibration curves. The arc plasma parameters (temperature and electron density) are similar when the spectra of dry residues of aqueous solutions, saliva, blood serum, and dry wine are excited. This provides direct (without digestion) determination of trace elements in these samples with the detection limits at a level of ìg/liter. When a sample of vegetable oil is deposited on the electrode, it is likely to be absorbed in depth and does not enter the arc plasma in full, which makes the direct analysis impossible. Nevertheless, the determination of trace elements in oils by the dry residue technique is possible after acid digestion of the sample.