Table 2. Analytical characteristics of calibration curve.
| Parameter | Sample volume | |||||
|---|---|---|---|---|---|---|
| 100 mL | 500 mL | 1000 mL | ||||
| Amount of exchanger (mg) | 50 | 65 | 50 | 65 | 50 | 65 |
| pH | 3.5 | 3.5 | 3.5 | 3.5 | 3.5 | 3.5 |
| Optimum [AHDDO] (M) | 1.0 × 10−4 | 1.0 × 10−4 | 5.0 × 10−5 | 5.0 × 10−5 | 2.5 × 10−5 | 2.5 × 10−5 |
| Stirring time (min) | 10 | 10 | 15 | 15 | 20 | 20 |
| Beer's range (μg mL−1) | 0.25–11.7 | 0.1–2.25 | 0.05–1.35 | 0.15–8.16 | 0.02–0.575 | 0.1–1.79 |
| Ringbom range (μg mL−1) | 0.75–10.8 | 0.25–2.00 | 0.15–1.20 | 0.30–7.90 | 0.1–0.550 | 0.30–1.55 |
| Molar absorptivity (L mol−1 cm−1) | 4.14 × 105 | 7.82 × 106 | 3.91 × 107 | 2.81 × 106 | 9.78 × 107 | 3.15 × 106 |
| Sandell's sensitivity (ng cm−2) | 0.0056 | 0.0012 | 0.0008 | 0.0038 | 0.0005 | 0.0022 |
| Intercept | −0.009 | 0.005 | 0.007 | −0.011 | −0.004 | 0.010 |
| Slope (ng mL−1) | 0.15 | 0.04 | 0.43 | 0.18 | 1.50 | 0.69 |
| Correlation coefficient (r) | 98.75 | 99.25 | 99.67 | 99.10 | 99.85 | 99.50 |
| Detection limit (ng mL−1) | 75.0 | 30.0 | 15.0 | 25.0 | 6.00 | 10.0 |
| Quantification limits (ng mL−1) | 250 | 100 | 50.0 | 80.0 | 20.0 | 35.0 |
| RSD (%) | 6.15 | 2.55 | 2.25 | 5.78 | 1.90 | 5.25 |