Tetramethylammonium perchlorate, known as 四甲基高氯酸铵, serves as an intermediate in organic and chemical synthesis. It is utilized in high-performance liquid chromatography (HPLC) as a mobile phase for the quantification of olanzapine, clozapine, and N-desmethylclozapine. Additionally, it acts as a supporting electrolyte in the electrochemical reduction of 1-bromodecane, 1-iodododecane, 2-iodooctane, and 2-bromooctane on a mercury cathode.