Table 2.
Parameters required for system suitability tests of TLC densitometric method
| Parameter | NPZ impurity B | NPZ | PHN | PHN impurity A | PHN impurity B |
|---|---|---|---|---|---|
| Rf | 0.18 | 0.35 | 0.49 | 0.63 | 0.83 |
| Resolution (Rs) | NA | 1.50 | 1.58 | 1.40 | 1.64 |
| Tailing factor (T) | 1.50 | 0.80 | 1.30 | 1.20 | 1.20 |
| Retention factor (k')a | 4.56 | 1.86 | 1.04 | 0.59 | 0.20 |
| Selectivity factor (α)b | NA | 2.45 | 1.79 | 1.76 | 2.95 |
| Column efficiency (N)c | 262.44 | 196.00 | 635.04 | 425.11 | 737.86 |
| Height equivalent to theoretical plate (mm) | 0.034 | 0.046 | 0.014 | 0.021 | 0.012 |
aRetention factor (k') = (1 − Rf)/Rf
bCalculation of α = k'2/k'1
cColumn efficiency (N) = 16 (z/w)2, where z is the migration length of the spot, w is the spot width