The solutions are intended for use as a certified reference material or calibration standard for the analysis of these elements in petroleum products or other organic matrices using inductively coupled plasma optical emission spectroscopy (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), rotating disc electrode atomic emission spectroscopy (RDE-AES), flame or furnace atomic absorption spectroscopy (AA or GFAA), and other techniques for elemental analysis.