RK (μg/mL)

Measured (mg/L, Mean ± S.D., n = 5)

C.V. (%)

Recovery (%)

Intra-day assay

0.05

0.5

2.5

Inter-day assay

0.05

0.5

2.5

0.0491 ± 0.0042

0.511 ± 0.022

2.42 ± 0.11

0.0488 ± 0.0049

0.504 ± 0.035

2.44 ± 0.14

8.6

4.3

4.5

10.0

6.9

5.7

98.2

102.2

96.8

97.6

100.8

97.6