A comparison of electrochemical sensors for the detection of nitrate ions.

Analytical method	Linear range	Low level of detection	Sample	Analyte	References
UV-visible spectrometry	1–100 μg mL−1	0.33 μg mL−1	Drinking water	Nitrate	22
UV-visible spectrometry	0.5–13.7 mg L−1	—	Municipal waste water	Nitrate	23
Ultraviolet (UV) light	0.08–4.0 mg L−1	0.04 mg L−1	Natural waters	Nitrate	24
UV-visible spectrometry	0.5–3.0 mg L−1	—	Agricultural soil samples and water samples	Phosphates	25
UV-visible spectrometry	0.5–5.0 μg mL−1	—	Soil/water	Phosphates	26
Ion chromatography	4.30–4.36 mg L−1	0.03 mg L−1	Soil extract	Nitrate	27
Ion chromatography	0.90–0.92 mg L−1	0.02 mg L−1	Soil extract	Phosphates	27
Ion chromatography	0.30 to 5.6 mg L−1	0.10 mg L−1	Natural waters	Potassium	28
Gas chromatography-mass spectrometry	0.02–10 mg L−1	3 μg L−1	Natural waters	Nitrate	29
Gas chromatography-mass spectrometry	0.5–208.5 mg L−1	0.176 mg L−1	Water	Potassium formate	30
Headspace gas chromatography (HS-GC)	—	2.5 mg kg−1	Soil sample	Phosphorus	31
High-performance liquid chromatography with UV detection	0.2–200 ppm	9.5 mg L−1	Environmental water samples	Nitrate	32
	0.2–200 ppm	1.33 mg L−1	Environmental water samples	Phosphate
Graphene-based field-effect transistor	0.001–100 mg L−1	1.1 μg L−1	Water	Nitrates	33
ZnO nanorods field-effect transistors (FETs)	1–5000 μM	1.0 μM	Nutrient solution or water	Phosphate	34
	2–25 000 μM	0.1 μM		Nitrates
	2–15 000 μM	0.4 μM		Potassium