Table 2 The Content, Reproducibility and Average Recovery of Samples.

From: Graphene nanoplatelets based matrix solid-phase dispersion microextraction for phenolic acids by ultrahigh performance liquid chromatography with electrochemical detection

Analyte

Content (mg/g)

Repeatability (RSD%) n = 3

Average recovery

Retention time

Peak area

Added (μg/mL)

Recovery%

Sodium danshensu

0.81

2.46

4.09

1

98.34

10

83.74

Protocatechuic aldehyde

0.37

1.85

3.33

1

95.60

10

85.31

Rosmarinic acid

0.52

2.32

3.89

1

90.83

10

86.45

Lithospermic acid

0.34

3.58

5.37

1

89.52

10

86.37

Salvianolic acid B

6.04

2.67

4.62

1

92.34

10

89.64

Salvianolic acid A

0.21

1.94

3.85

1

90.66

10

82.34