Table 1 Optimization of the chromatographic conditions for separation of the studied analytes by the proposed HPLC method
Parameter | No. of theoretical plates | Resolution | Tailing factor | Selectivity factor (α) | ||
|---|---|---|---|---|---|---|
LOR | DSL | LOR | DSL | |||
pH of the mobile phase | ||||||
 2.5 | 1707 | 1738 | 3.25 | 1.34 | 1.23 | 1.75 |
 3.0 | 1811 | 1910 | 3.41 | 1.32 | 1.22 | 1.90 |
 3.5 | 2328 | 2693 | 4.93 | 1.31 | 1.21 | 1.94 |
 4.0 | 1601 | 2433 | 2.13 | 1.39 | 1.29 | 1.32 |
 5.0 | 1908 | 2508 | 2.94 | 1.44 | 1.3 | 1.63 |
 6.0 | Unresolved peaks | |||||
SDS concentration (M) | ||||||
 0.05 | 1584 | 1667 | 5.66 | 1.58 | 1.47 | 2.26 |
 0.1 | 1453 | 1627 | 4.91 | 1.52 | 1.44 | 1.94 |
 0.12 | 1501 | 2133 | 4.72 | 1.3 | 1.23 | 1.87 |
 0.15 | 2328 | 2693 | 4.93 | 1.31 | 1.21 | 1.94 |
 0.175 | 1918 | 2216 | 3.64 | 1.45 | 1.28 | 1.42 |
n-Butanol concentration (%v/v) | ||||||
 5% | 692 | 727 | 4.52 | 2.03 | 1.77 | 1.76 |
 8% | 1575 | 1825 | 4.12 | 1.29 | 1.28 | 1.71 |
 10% | 2328 | 2963 | 4.93 | 1.31 | 1.21 | 1.94 |
 12% | 1487 | 1938 | 3.83 | 1.45 | 1.33 | 1.59 |
Flow rate (mL/min) | ||||||
 0.8 | 2190 | 2105 | 5.36 | 1.36 | 1.34 | 2.21 |
 1.0 | 1887 | 2328 | 5.12 | 1.39 | 1.29 | 2.16 |
 1.2 | 2328 | 2693 | 4.93 | 1.31 | 1.21 | 1.94 |
 1.5 | 1558 | 2117 | 3.93 | 1.20 | 1.14 | 1.62 |
Column temp. | ||||||
 25 | 2328 | 2693 | 4.93 | 1.31 | 1.21 | 1.94 |
 35 | 1962 | 2206 | 4.02 | 1.98 | 2.11 | 1.77 |
 45 | 884 | 679 | 5.48 | 2.23 | 2.4 | 2.20 |