Method I Method II
Concentration (ng mL-1) RT (min) Area EP RT (min) Area EP
5.0 7.133 0.6390 15430 6.99 0.6718 17877
  7.133 0.6417 15506 6.99 0.6799 17733
  7.133 0.6354 15430 7.01 0.6837 17866
  7.133 0.6399 15468 7.01 0.6714 17722
  7.137 0.6190 15559 7.01 0.6651 17801
  7.137 0.6469 15444 7.01 0.6800 17801
Mean
%RSD
SE
7.134
0.0289
0.0008
0.6369
1.504
0.0039
15472
0.3301
20.85
7.003
0.1474
0.0042
0.6753
1.037
0.0028
17800
0.3628
26.36
RT= Retention time, EP = Theoretical plates, RSD= Relative standard deviation, SE= Standard error
Table 4: Result analysis of injection precision repeatability of method I and method II.