Nitrate Nitrogen Content Assay Kit (Sulfanilamide, Colorimetric Method)

Cat. No.: N1510390

GRADE & PURITY BioReagent

Descripción general

Nitrate nitrogen is the primary nitrogen source for plants. The nitrate nitrogen content in plant tissues reflects the supply of nitrate nitrogen in the soil and can serve as an indicator of soil nitrogen fertility. Measuring the nitrate nitrogen content in plants not only reveals the nitrogen nutrition status of the plants but is also significant for assessing the quality of vegetables and processed products derived from plants.

Detection Principle

Nitrate is reduced to nitrite by a reducing agent. The nitrite then reacts with sulfanilic acid and naphthylamine to form a rose-red azo compound. The intensity of the color is proportional to the nitrogen content within a certain range. The absorbance is measured at 520 nm using a spectrophotometer, and the nitrate nitrogen content of the sample is calculated based on a standard curve. This kit is primarily used to determine nitrate nitrogen content in plant tissues, serum, tissue samples, etc. It is for research use only and is not suitable for clinical diagnosis or other purposes.

N1510390	Component	50T	Storage
N1510390A	Nitrate Nitrogen Standard (200 µg/mL)	1 mL	2-8℃.
N1510390B	Nitrate Nitrogen Extraction Solution	250 mL	RT.
N1510390C	Assay Buffer	250 mL	RT.
N1510390D	Sulfanilamide Mixture Powder	5 g	RT. Store in the dark.

Reagents, consumables and Equipments not provided

• Spectrophotometer (capable of measuring absorbance at 520 nm)
• Electronic balance, scissors, centrifuge, centrifuge tubes, test tubes, filter paper, cuvettes
• Experimental materials: Plant tissues (soybean, corn petioles, etc.), blood, urine, etc.
• Distilled water
  

Operating Steps

1. Sample Preparation

1.1 Plant Samples

Take 0.1–0.15 g of fresh plant tissue (normal or under stress), wash, dry, and cut into 1–2 mm pieces. Add 4 mL of Nitrate Nitrogen Extraction Solution, vortex vigorously for 2–4 minutes, and allow to stand until clear. The supernatant is the nitrate nitrogen extract. Store at 4°C for use.

1.2 Serum and Urine Samples

After preparation by conventional methods, they can be directly used for assay with this kit. Store at 4°C for nitrate nitrogen detection.

1.3 High-Activity Samples

If the sample contains a high concentration of nitrate nitrogen, dilute appropriately with Nitrate Nitrogen Extraction Solution or distilled water.

2. Preparation of Nitrate Nitrogen Standard Series

Dilute the Nitrate Nitrogen Standard (200 µg/mL) with distilled water to 20 µg/mL. Then continue diluting according to the table below:

Tube No.	1	2	3	4	5	6
Nitrate Nitrogen Standard (20 µg/mL) (mL)	0.05	0.1	0.2	0.3	0.4	0.5
Distilled Water (mL)	0.45	0.4	0.3	0.2	0.1	0
Nitrate Nitrogen Concentration (µg/mL)	2	4	8	12	16	20

3. Sample Addition

Set up blank, standard, and test tubes according to the table below. Add solutions in the specified order, taking care to avoid bubbles. If the nitrate nitrogen concentration in the sample is too high, reduce the sample volume or dilute appropriately before measurement. It is recommended to set up duplicate tubes for sample detection.

Substance Added (mL)	Blank Tube	Standard Tube	Test Tube
Distilled Water	0.5	—	—
Nitrate Nitrogen Standard Series (Tubes 1–6)	—	0.5	—
Sample	—	—	0.5
Assay Buffer	4.5	4.5	4.5

Mix thoroughly.

Sulfanilamide Mixture Powder

0.1g

0.1g

0.1g

4. Nitrate Nitrogen Measurement

Vortex vigorously for 1 minute and let stand for 10 minutes. Filter through double-layer filter paper into a new centrifuge tube. Centrifuge at 4000 rpm for 5 minutes, take the supernatant and centrifuge again. Transfer the supernatant to a 1 cm pathlength cuvette. Zero the spectrophotometer with the blank tube and measure the absorbance of the standard and test tubes at 520 nm (recorded as A_Standard and A_Test).

5. Result Calculation

Using the nitrate nitrogen standard series (Tubes 1–6) concentrations (µg/mL) as the x-axis and the corresponding absorbance values as the y-axis, plot a standard curve. Calculate the nitrate nitrogen content of the sample based on the absorbance of the test tube. Use the following formulas:

For plant tissue samples:

Nitrate Nitrogen (µg/g) = C × V / m

Parameter Explanation:

C: Nitrate nitrogen concentration of the sample obtained from the standard curve (µg/mL)

V: Total volume of the sample extract (mL); 4 mL in this method.

m: Sample mass (g)

For serum, urine, and other liquid samples:

Nitrate Nitrogen (µg/mL) = C × N

Parameter Explanation:

C: Nitrate nitrogen concentration of the sample obtained from the standard curve (µg/mL)

N: Dilution factor

Precautions

1. Experimental materials should be as fresh as possible. If not measured immediately after collection, store at 4°C.

2. Assay Buffer is volatile; store tightly sealed.

3. If a spectrophotometer is unavailable, a standard microplate reader can also be used.

4. If the measured sample concentration is too high, dilute the sample with Nitrate Nitrogen Extraction Solution or distilled water and repeat the measurement.

5. For your safety and health, please wear a lab coat and disposable gloves during operation.

6. Please use the reagent as soon as possible after opening to avoid affecting subsequent experimental results.

Almacenamiento y envío

Condiciones de almacenamiento de almacenamiento

Store at 2-8°C,Protected from light,Room temperature

Enviado en

Wet ice

Estabilidad y almacenamiento

Each component has a shelf life of 1 year under corresponding storage conditions.