The GB/T 29056-2012 standard specifies a method for the determination of trace elements such as boron, aluminum, phosphorus, vanadium, chromium, manganese, iron, cobalt, nickel, copper, molybdenum, arsenic, and antimony in trichlorosilane (SiHCl) for silicon epitaxy by Inductance Coupled Inductively Coupled Plasma Mass Spectrometer (ICP-MS) (ICP-MS). The standard applies to the determination of these trace elements in trichlorosilane for silicon epitaxy. The method includes the formation of a stable complex between acetonitrile and metal chlorides, the volatile separation of the matrix by nitrogen carrier, the treatment of the residue by hydrofluoric acid and nitric acid, and finally the determination by ICP-MS. The standard details the purity requirements and processing steps of the required reagents to ensure the accuracy and Reliability of the assay.