GB/T 32737-2016Determination of nitrate nitrogen in soil—Ultraviolet spectrophotometry method (English PDF)

1 Scope

This standard specifies the principle, reagent, instrument, analysis procedure and result of the determination of nitrate nitrogen in soil leaching solution by ultraviolet spectrophotometry.

Calculation and representation, precision, quality assurance and control.

This standard applies to the determination of nitrate in soil. The detection limit of soil nitrate nitrogen was 0.5mg/kg, and the limit of quantification was

1mg/kg.

2 normative reference documents

The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this article

Pieces. For undated references, the latest edition (including all modifications) applies to this document.

GB/T 6682 Analytical laboratory water specifications and test methods

HJ634 Soil Ammonia Nitrogen, Nitrite Nitrogen, Nitrate Nitrogen Determination Potassium Chloride Solution Extraction-Spectrophotometry

Method for determination of soil moisture

Determination of pH in soil by NY/T 1377

3 terms and definitions

The following terms and definitions apply to this document.

4 principle

The use of nitrate leachate in the soil near the wavelength of 220nm absorption and absorbance of the size and nitrate concentration

The nitrite content was quantitatively determined. Using the dissolved organic matter at 220nm and 275nm wavelength are absorbed,

While the nitrate ion at 275nm wavelength does not absorb the characteristics of the soil leaching solution at 275nm absorbance, multiplied by a school

The positive factor (f value) is used to eliminate the interference caused by the absorption of organic matter at 220 nm.

5 reagent

Unless otherwise specified, only analytical reagents shall be used in the analysis, and the water used shall comply with the requirements for Grade 3 water in GB/T 6682.