2. Materials and methods
2.1. Sample collectionand preparation of lab-made mock SLBZS samples
Ten herbal materials of SLBZS were purchased from a Beijing Tongrentang drug store (Figure 1) . DNA barcoding techniques were used to obtain ITS2, psbA-trnH , matK , and rbcL of the herbal materials. These barcodes are used to verify the accuracy of the original species of herbal materials on the one hand, and on the other hand to verify the accuracy of subsequent sequencing assembly (Supplementary Table 1 ). Subsequently, these authenticated herbal materials were used to make mock samples according to the preparation method under the ”Shenling Baizhu San” item of the Chinese Pharmacopoeia (2020 edition). The proportion of each medicinal material listed in the preparation is shown in Supplementary Table 2 . Two mock samples were made and named HSZY159 and HSZY171, respectively. To verify the sensitivity of the method, 6.4 mg powder of Panax quinquefolius root was added to each 100 mg of the mock sample HSZY171 in the same proportion as the lowest proportion of the prescribed ingredient in SLBZS. In addition, four pharmaceutical samples of SLBZS with different production batch numbers were collected from different pharmacy stores, and were marked as A03, HSZY152, HSZY191, and HSZY192.