Table 4.
Contents of heavy metals in four kind Chinese herbal medicines and the excessive situation of harmful elements
| Elements | Element content in four kinds Chinese herbal medicines (mg kg−1) | Limiting Value 1 |
Limiting Value 2 |
Mean excess # | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| AL | SB | RA | SG | AL | SB | RA | SG | |||
| Cr | 4.58 ± 4.55 | 0.76 ± 0.23 | 0.05 ± 0.04 | 0.28 ± 0.10 | – | – | – | – | – | |
| Ni | 4.12 ± 2.11 | 4.53 ± 1.21 | 5.27 ± 0.76 | 2.98 ± 0.48 | – | – | – | – | – | |
| Cu | 24.73 ± 9.619 | 10.27 ± 2.02 | 82.93 ± 17.07 | 13.56 ± 6.22 | 20 | 20 | 23.64% | / | 250.80% | / |
| Zn | 58.11 ± 28.26 | 14.92 ± 2.56 | 50.49 ± 8.79 | 13.21 ± 3.85 | – | – | – | – | – | – |
| As | 0.19 ± 0.71 | 0.10 ± 0.02 | 0.04 ± 0.01 | 0.03 ± 0.01 | 2 | 2 | / | / | / | / |
| Cd | 0.45 ± 0.10 | 0.06 ± 0.01 | 0.24 ± 0.03 | 0.26 ± 0.15 | 1 | 0.3 | 48.67% | / | / | / |
| Hg | 0.20 ± 0.08 | 0.36 ± 0.13 | 0.20 ± 0.08 | 0.22 ± 0.12 | 0.2 | 0.2 | / | 81.99% | / | 8.00% |
| Pb | 1.74 ± 0.67 | 0.79 ± 0.26 | 7.01 ± 1.63 | 0.86 ± 0.63 | 5 | 5 | / | / | 40.29% | / |
Annotation: "" indicates that there is no relevant data provision in the soil quality standard; "/" indicates that there is no excess; Limiting value 1 reference (Commission, 2020), Limiting value 2 reference (MFTEC 2005); # the calculation formula is: (mean value of measured values of element content-pharmacopoeia limit)/ pharmacopoeia limit × 100%. Values were highlight with bold, which means higher than the standards instead of representing a statistical difference