Nitrate is one of the nitrogen - containing substances absorbed by plants. Nitrate is reduced in roots ,
branches or leaves, depending on plant type and environmental conditions. Detecting nitrate nitrogen
content in plants is significant to understand the nitrogen metabolism mechanism.
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NO3 can react with salicylic acid to form nitrosalicylic acid under the condition of concentrated acid,
which shows yellow under the condition of pH>12. Within a certain range, the color depth is proportional
to the content.
Reagents and Equipments Required but Not Provided:
Spectrophotometer, water bath, centrifuge, transferpettor, 1 mL glass cuvette, mortar/homogenizer, ice and
distilled water.
Sample preparation:
Add 1 mL of distilled water into 0.1 g of tissue, fully grind at RT and put it in 90℃ water bath for 30 min,
shaking during the bath. Or put in 90℃ shaker, centrifuge at 12000 g, 25℃ for 15 min after cooling. Take
the supernatant on ice for test.
