Table 6.
Comparison of different sample preparation techniques for the quantification of cobalt and nickel in urine (n = 6).
| Sample | Sample preparation procedure |
|||||
|---|---|---|---|---|---|---|
| С Co (228.616), ng/mL |
С Ni (231.604), ng/mL |
|||||
| Direct analysis | 5-fold dilution | Microwave mineralization | Direct analysis | 5-fold dilution | Microwave mineralization | |
| 5 ng/mL spiked distilled water | 5.0 ± 0.5 | 5.0 ± 0.4 | 4.0 ± 0.5 | 6.0 ± 1.0 | 5.0 ± 0.4 | 5.0 ± 0.6 |
| Blank | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. |
| 1 ng/mL spiked blank | n.d. | n.d. | n.d. | n.d. | n.d. | 1.0 ± 0.1 |
| 5 ng/mL spiked blank | 8.0 ± 1.8 | 4.0 ± 0.3 | 4.0 ± 0.5 | 9.0 ± 2.0 | 5.0 ± 0.4 | 4.0 ± 0.5 |
| 10 ng/mL spiked blank | 14 ± 3 | 8.0 ± 0.6 | 7.0 ± 0.8 | 13 ± 2 | 9.5 ± 0.8 | 8.5 ± 1.0 |
| Sample after taking single dose of vitamins | 8.5 ± 2.0 | 5.7 ± 0.4 | 5.8 ± 0.7 | 11 ± 2 | 7.8 ± 0.6 | 8.2 ± 1.0 |
| Sample after taking double dose of vitamins | 13 ± 2 | 11 ± 1 | 11 ± 1 | 21 ± 4 | 15 ± 1 | 17 ± 2 |
| Sample after taking double dose of vitamins and 10 ng/mL spike | 34 ± 6 | 16 ± 1 | 20 ± 2 | 27 ± 5 | 20 ± 2 | 21 ± 2 |
∗n.d. – not detected.