The selectivity of TRFIA for measurement of Pb in plasma.
| Metal | IC50a (pg mL−1) | Cross reactivityb (%) |
|---|---|---|
| Lead, Pb | 47c | 100c |
| Zinc | 750 | 6.2 |
| Nickel | 1850 | 2.5 |
| Mercury | 4500 | 1.0 |
| Cadmium | NDd | ND |
| Manganese | ND | ND |
| Magnesium | ND | ND |
| Iron | ND | ND |
| Calcium | ND | ND |
| Copper | ND | ND |
| Chromium | ND | ND |
| Selenium | ND | ND |
a
IC50 is the concentration of metal-DTPA complex which inhibits 50% of the maximum RFI in the TRFIA.
b
Calculated as IC50 [Pb]/IC50 [metal] × 100.
c
Values are the mean of triplicate determinations.
d
Not determined because it was more than 1000 pg mL−1.