Amount of NO− 3 (mg∙L⁻¹)

Sample

Ion chromatography

Ion-selective electrode

Lettuce 1

3.48 ± 0.83

3.23 ± 0.67

Cauliflower 1

2.87 ± 0.23

2.41 ± 0.19

Spinach 1

17.20 ± 0.72

16.92 ± 1.32

Arugula 1

8.61 ± 0.64

8.38 ± 0.69