This standard specifies the determination of chlorine nitrogen (oxazepam), nitrazepam, oxazepam, clonazepam, lorazepam, estazolam, alprazolam, triazolam and diazepam in feed Liquid chromatography-tandem mass spectrometry (LC-MS/MS) of the contents of 9 kinds of benzodichloride (Cangjiazhuo) drugs including Pan. This standard applies to compound feed, concentrated feed and additive premixed feed. The LC-MS/MS quantitative limit is 0.03mg/kg.