Next, the TCCA and sodium bromide leaching method was applied to a variety of other metals and metal sulfides (Fig. ). This is important when leaching substrates such as ore or electronic waste that contain many types of metals, so the composition of the leaching solution can be anticipated. Accordingly, gold, copper, tin, silver, nickel, iron, zinc, and aluminum metals and sulfides of iron, zinc, copper and silver were separately treated with the TCCA and sodium bromide leach solution (5.08 mmol TCCA, 2.54 mmol NaBr, and 127 µmol metal or metal sulfide in 40 mL water). The experiments were run for 6 hours and then analyzed by inductively coupled plasma mass spectrometry (ICP-MS) or inductively coupled plasma-optical emission spectrometry (ICP-OES). All metals or metal sulfides leached into solution except for tin, silver, and silver sulfide. It was thought that these metals and metal sulfides still react, but form insoluble species such as tin oxide or silver halides. In contrast, quantitative leaching of gold, copper, zinc and zinc sulfide was observed. Partial leaching was observed for nickel, iron, and aluminum metal and also iron sulfide and copper sulfide. These results indicate that the TCCA leaching solution is not selective for gold, so the leaching technique must be coordinated with measures to preconcentrate gold where possible and then use a selective sorbent to recover the gold, as described below.