| As | Hg | Cr | Pb | Zn |
Experimental | 1.5 | 0.54 | 26.5 | 26 | 167.2 |
Certified | 1.7 | 0.51 | 28 | 30 | 165 |
% Recovery | 88% | 106% | 95% | 87% | 101% |