It is because that sodium azide only quenches the CL signal of the working reaction, whereas other similar compounds quench the CL signal of both working reaction and reference reaction.

• 这是因为叠氮化钠仅淬灭“工作反应”的化学发光信号；而其它的自由基淬灭剂则同时淬灭“工作反应”和“参比反应”的化学发光信号.