Parameter

AP1

AP2

AP3

Color

yellow

yellow

yellow

The pH range of education and extraction

2.1 - 6.5

2.0 - 6.3

2.1 - 5.5

The pH range of maximum extraction

3.5 - 5.0

3.3 - 4.9

3.0 - 4.7

Concentration of DTP: mol∙L−1

1.0 × 10−3

1.0 × 10−3

1.0 × 10−3

Concentration of An: mol∙L−1

8 × 10−4

8 × 10−4

8 × 10−4

Organic solvent

Chloroform

Chloroform

Chloroform

Extraction time

3 min

3 min

3 min

λmax(nm)

440

438

435

Molar absorptivity (L∙mol1∙cm1)

2.9 × 104

2.8 × 104

2.6 × 104

Sandell’s sensitivity (µg∙cm2)

0.0032

0.0033

0.0035

R, %

97.9

97.8

97.6

The equation of calibration curves

0.023 + 0.30x

0.025 + 0.29x

0.038 + 0.27x

lgKe

5.82

5.76

5.75

lgKEx

10.06

9.95

9.82

Stability constant (β)

8.4

8.3

8.2

Beer’s law range (µg∙ml1)

0.05 - 4.0

0.05 - 3.8

0.06 - 3.8

Correlation coefficient

0.9985

0.9982

0.9975

Limit of detection (LOD): ng∙mL−1

11

12

14

Limit of quantification (LOQ): ng∙mL−1

36

40

45