1. Tetramethylsilane is commonly used as an internal standard in NMR spectroscopy.
四甲基硅烷通常用作核磁共振光谱中的内标。

2. The synthesis of tetramethylammonium chloride involves the reaction of quaternary amine with hydrochloric acid.
四甲基氯化铵的合成涉及到季铵盐与盐酸的反应。