Characteristics | DTMP | DTEP | DTBP | ||||||
AP1 | AP2 | AP3 | AP1 | AP2 | AP3 | AP1 | AP2 | AP3 | |
Color | Red | Red | Red | Red | Red | Red | Red | Red | Red |
λmax | 525 | 520 | 516 | 530 | 528 | 520 | 534 | 530 | 525 |
pH range | 2.5 - 8.5 | 2.3 - 8.4 | 2.2 - 8.3 | 2.3 - 8.3 | 2.2 - 8.2 | 2.0 - 8.1 | 2.6 - 8.8 | 2.5 - 8.5 | 2.2 - 8.4 |
Optimum pH range | 4.6 - 5.8 | 4.5 - 5.5 | 4.3 - 5.4 | 4.4 - 5.3 | 4.3 - 5.2 | 4.1 - 5.1 | 4.8 - 5.9 | 4.6 - 5.8 | 4.5 - 5.5 |
Ε × 104 (L∙mol−1∙cm−1) | 5.08 | 4.85 | 4.60 | 5.20 | 5.08 | 4.92 | 5.35 | 5.25 | 5.12 |
Degree of extraction (%) | 98.7 | 98.5 | 98.4 | 98.7 | 98.6 | 98.5 | 98.7 | 98.6 | 98.5 |
Working range/µg cm−3 | 2 - 100 | 2 - 90 | 2 - 90 | 2 - 110 | 2 - 100 | 2 - 100 | 2 - 120 | 2 - 110 | 2 - 110 |
lg ke | 6.5 | 6.4 | 6.4 | 6.3 | 6.3 | 6.2 | 6.3 | 6.3 | 6.2 |
Stability constant (β) | 10.35 | 10.15 | 10.06 | 10.26 | 10.10 | 9.95 | 10.45 | 10.23 | 10.18 |
lgKex | 12.84 | 12.75 | 12.66 | 12.75 | 12.64 | 12.58 | 12.95 | 12.84 | 12.75 |