Table 8 Experimental data of the molar absorptivity (ε), Specific absorptivity [17] (a), Sandell's sensitivity [18] (S), lowest detectable concentration (LDC) and statistical results for Ia and Ib and other literature chelates
Chelate | Metal | \(\varepsilon\) × 10–4 l. mol−1.cm−1 | a ml.g−1.cm−1 | I | s | R2 | S \(\times\) 10–3 \(\mu\) g/cm2 | \(\mu g/10\) ml up to | LDC, ppm |
|---|---|---|---|---|---|---|---|---|---|
Ia | Co(II) | 1.49 | 0.25 | 0.027 | 0.012 | 0.9981 | 3.59 | 18.7 | 0.50 |
Ni (II) | 1.88 | 0.32 | 0.036 | 0.035 | 0.9921 | 3.13 | 25.0 | ||
Cu(II) | 1.55 | 0.24 | − 0.015 | 0.024 | 0.9970 | 4.17 | 40.0 | ||
Zn(II) | 1.20 | 0.18 | 0.014 | 0.023 | 0.9950 | 5.47 | 35.0 | ||
Ib | Co(II) | 2.25 | 0.38 | 0.022 | 0.018 | 0.9981 | 2.61 | 18.5 | 0.50 |
Ni (II) | 3.60 | 0.55 | − 0.008 | 0.010 | 0.9991 | 1.80 | 18.9 | ||
Cu(II) | 2.04 | 0.31 | − 0.036 | 0.020 | 0.9980 | 3.10 | 35.0 | ||
Zn(II) | 1.73 | 0.26 | − 0.002 | 7 × 10–4 | 1.0000 | 3.80 | 22.0 | ||
4-(2-pyridylazo) resorcinol (PAR) [2] | Co(II) | – | – | 0.069 | – | 0.9985 | – | – | – |
Ni (II) | – | – | 0.071 | – | 0.9910 | – | – | – | |
Cu(II) | – | – | 0.075 | – | 0.9960 | – | – | – | |
Zn(II) | – | – | 0.080 | – | 0.9995 | – | – | – | |
2-Carboxy-2′-hydroxy-5′-sulfoformazyl-benzene (Zincon) [2] | Co(II) | – | – | 0.045 | – | 0.9870 | – | – | – |
Ni (II) | – | – | 0.046 | – | 0.9988 | – | – | – | |
Cu(II) | – | – | 0.055 | – | 0.9987 | – | – | – | |
Zn(II) | – | – | 0.051 | – | 0.9994 | – | – | – | |
2-(4-biphenyl) Imidazo[1,2-Pyrimidine-3-Hydrazone [3] | Cu(II) | 0.0175 | – | 0.060 | – | 0.9909 | 2.78 × 103 | – | 0.122 |
4-(2-pyridylazo) resorcinol (PAR) [1] | Co(II) | – | – | – | – | – | – | – | 0.59 |
dimethylglyoxime (DMG) [1] | Ni (II) | – | – | – | – | – | – | – | 5.87 |
bathocuproine (Bc) [1] | Cu(II) | – | – | – | – | – | – | – | 0.32 |
Extended Kalman filter spectrophotometry [4] | Cu(II) | – | – | 0.284 | – | 0.9964 | – | – | 0.50 |
Co(II) | – | – | -0.144 | – | 0.9987 | – | – | 0.30 |