|  |  |  | First test |  | Second test | ||||
---|---|---|---|---|---|---|---|---|---|---|
Sample | Description spot | Area (cm2) | Â | ng/mL (NaOH) | ng | ng/cm2 | Â | ng/mL (NaOH) | ng | ng/cm2 |
1 | Work place | 3900 | Â | 0.28 | 45 | 0.012 | Â | nd | - | - |
2 | Air foil | 1463 | Â | 0.54 | 86 | 0.059 | Â | nd | - | - |
3 | Floor in front | 4900 | Â | 0.17 | 27 | 0.006 | Â | nd | - | - |
4 | Table | 2442 | Â | nd | - | - | Â | nd | - | - |
5 | Office area | 3060 | Â | nd | - | - | Â | nd | - | - |
6 | Floor | 4900 | Â | 0.15 | 24 | 0.005 | Â | 0.24 | 38 | 0.008 |