Table 3 Intra-day and inter-day precision of derivative ratio, delta absorbance, first derivative of delta A for the determination of SF in presence of VP and for spectrophotometric (UV) and spectrofluorimetric (flu) determination of VP in presence of SF using NBD-Cl and MBTH method

Intra-day precision

10

100.56 ± 0.64

99.14 ± 1.16

99.74 ± 1.817

0.64

1.17

1.82

0.56

−0.86

−0.26

30

101.64 ± 0.94

101.21 ± 1.52

101.98 ± 0.958

0.92

1.51

0.94

1.64

1.21

1.98

60

102.11 ± 0.19

101.18 ± 1.86

101.59 ± 1.36

0.18

1.84

1.34

2.11

1.18

1.59

Inter-day precision

10

100.37 ± 1.83

99.68 ± 0.58

100.77 ± 1.34

1.82

0.58

1.33

0.37

−0.31

0.77

30

101.29 ± 0.82

100.77 ± 1.02

101.55 ± 1.34

0.8

1.01

1.32

1.29

0.77

1.32

60

102.52 ± 0.44

101.02 ± 0.48

101.16 ± 1.02

0.42

0.47

1.01

2.52

1.02

1.16

Determination of VP in presence of SF

VP (μg/mL)

Mean % recovery ± SD

RSD %^(a)

Er (%)^(b)

NBD-Cl

MBTH

NBD-Cl

MBTH

NBD-Cl

MBTH

UV

Flu

UV

UV

Flu

UV

UV

Flu

UV

Intra-day precision

20 μg/ml (UV)

4 μg/ml (flu)

99 ± 1

100.28 ± 1.64

100.33 ± 1.91

1.01

1.63

1.9

−1

0.28

0.33

50 μg/ml (UV)

10 μg/ml (flu)

99.2 ± 1.113

98.98 ± 0.82

100.97 ± 1.04

1.122

0.83

1.03

−0.8

−1.01

0.97

150 μg/ml (UV)

15 μg/ml (flu)

100.66 ± 1.75

99.37 ± 0.66

100.32 ± 0.75

1.74

0.67

0.75

0.66

−0.62

0.32

Inter-day precision

20 μg/ml (UV)

4 μg/ml (flu)

99.88 ± 1.495

101.19 ± 1.56

99.08 ± 1.91

1.497

1.54

1.93

−0.11

1.19

−0.92

50 μg/ml (UV)

10 μg/ml (flu)

99.51 ± 0.922

99.54 ± 0.94

99.80 ± 1.00

0.927

0.95

1

−0.488

−0.46

−0.2

150 μg/ml (UV)

15 μg/ml (flu)

100.44 ± 1.236

99.17 ± 0.48

99.66 ± 0.79

1.23

0.49

0.79

0.44

−0.83

−0.34