| Substance |
Preparation |
Analytical method |
Minimum limit of determination |
| Hg |
Wet digestion |
Atomic absorption spctrometric method after reduction-generation as Mercury gas |
1ppm |
| Cd |
Wet digestion
(dissolved completely) |
Atomic absorption spectrometric method |
10ppm |
| Pb |
10ppm |
| Cr6+ |
Extraction in boiling water |
Diphenylcarbazide spectrophotometric method |
0.01µg/cm2 |