GB/T 42488-2023Soil quality—Determination of nitrogen-15 abundance of inorganic nitrogen in soil—Stable isotope ratio mass spectrometry (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules for Standardization Documents" drafting.

1 Scope

This document describes the determination of three inorganic states in soil using trace gas preconcentration-isotope ratio mass spectrometry (TGC-IRMS)

Nitrogen (ammonium nitrogen NH4, nitrate nitrogen NO3- and nitrite NO2-) 15N abundance method.

This document is applicable to the uniformly mixed soil after the 15N tracer test (f15N<=30%).

In this document, the quantitative limit of ammonium nitrogen in soil is 6 mg/kg, the quantitative limit of nitrate nitrogen is 3 mg/kg, and the quantitative limit of nitrite nitrogen is 0.15 mg/kg.

2 Normative references

The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, dated references For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 6379.2 Accuracy of measurement methods and results (trueness and precision) - Part 2: Determination of repeatability of standard measurement methods Fundamental methods of sex and reproducibility

GB/T 6682 Analytical laboratory water specifications and test methods

GB/T 37885 Classification of Chemical Reagents ISO /T S14256-1.2003 Soil Quality Potassium Chloride Solution Extraction Determination of Nitrate Nitrogen, Nitrite Nitrogen and Ammonium in Fresh Soil

3 Terms and Definitions

This document does not have terms and definitions that need to be defined.

4 Symbols and abbreviations

The following symbols and abbreviations apply to this document. f15N. 15N abundance, the percentage (%) of 15N atoms in the total number of nitrogen atoms.

R45.Ion current intensity ratio, the ratio of the ion current intensity I45 with a mass-to-charge ratio (m/z) of 45 to the ion current intensity I44 with a mass-to-charge ratio of 44 (I45/I44). Mass Spectrometer).