用硫化鋅試紙代替硫化氫来檢驗重金屬,不仅避免了硫化氫的不良臭味,並且因硫化鋅本身亦为难溶性化合物,由它解离而得的硫离子濃度很小,故与多种重金屬离子(其硫化物液解度积比硫化鋅更小者)作用时生成沉淀的速度亦慢,这样就可观察到一系列的顏色变化(其中有某些重金屬如改用硫化鈉、硫化銨等試剂是会观察不到的),这就使那些最終都生成黑色硫化物的重金屬离子,在反应开始时就可互相区別了。由于在药房处方制剂中,兩种以上的重金屬药物混合在一起的情况是極少的,因此使用它来作鑑別反应是很方便的。即 The use of zinc sulfide test paper instead of hydrogen sulfide to test heavy metals not only avoids the bad odors of hydrogen sulfide, but also because sulphide zinc itself is also a hardly soluble compound, and the sulfide ion concentration resulting from its dissociation is very small, so it is associated with various heavy metal ions. (The sulfid solution solution product is smaller than ZnS). The rate of precipitation during the process is also slow, so that a series of color changes can be observed (among them some heavy metals such as sodium sulfide, ammonium sulfide, etc. The agents are not observable. This allows the heavy metal ions that eventually generate black sulfides to be distinguished from each other at the beginning of the reaction. Since in the pharmacy prescription formulation, the combination of two or more kinds of heavy metal drugs is extremely rare, it is convenient to use it as a differential reaction. which is