Solution:	Storage temperature
Potassium phosphate buffer 1 M pH 7.5-	20 °C
NADPH 50 mM in NaOH 20 mM-	80 °C
Nitrate reductase (5 U ml-1 in Potassium phosphate buffer 0.1 M)-	80 °C
PES 0.25 mM-	80 °C
Sulfanilamide 1% (w/v) in phosphoric acid 5%	4 °C
NNEDA 0.02% (w/v)	4 °C
Nitrate standards-	80 °C
Nitrate Standards: 0, 0.2, 0.4, 0.8, and 1.6 mM in 70% ETOH with 10 mM MES pH 5.9