Table 1 Trace metals detected in MWCNTs used in this study (ND: not detected)
Element | CNT-S (ppm) | CNT-L (ppm) | Detection limit (ppm) |
|---|---|---|---|
Na | ND | 40 | 20 |
Mg | ND | 300 | 10 |
Al | ND | 30 | 10 |
Ca | 30 | 100 | 20 |
Cr | ND | 400 | 10 |
Mn | ND | 30 | 10 |
Fe | 50 | 2,000 | 10 |
Co | 30 | 10 | 10 |
Ni | 4,000 | 2,000 | 10 |
Mo | 50 | 15,000 | 10 |
La | 20 | 10 | 10 |