Initial amount (ng)

Excess drug
added to the
 analyte (%)

Amount
 recovered
(ng )

%Recovery

% R.S.D.

400

0

401.80

100.45

0.80

400

50

603.56

100.59

1.49

400

100

807.50

100.93

1.42

400

150

1001.27

99.51

0.52