US 11,561,209 B2Granted

Method for simultaneous determination of nitrogen and oxygen isotope compositions of natural nitrate and nitrite

AssigneeShaanxi University of Science and Technology

InventorsYouping Zhou, Bo Wang, Zhenyu Zhu, Ran Ma, Yan Huang, Shuai Zheng, Ying Wang, Benli Zhang

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method for simultaneous determination of nitrogen and oxygen isotope compositions of natural nitrate and nitrite, which quantitatively converts natural nitrate and nitrite into an organic ester and a nitro-compounds respectively, and then nitrate and nitrite δ18O and δ15N are simultaneously determined by adopting a gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry coupling technology (GC/Py/GC/IRMS). According to the method for simultaneously determining the nitrogen and oxygen isotope compositions of the natural nitrate salt and nitrite salt, the small amount of sample does not result in the loss, acquisition, exchange and fractionation of nitrogen and oxygen.

Claims13

Dependent claims

A system for simultaneous determination of nitrogen and oxygen isotope compositions in nitrate and nitrite, wherein the system comprises:

a nitrate and nitrite enrichment unit, configured for enriching the nitrate and the nitrite in a sample to be detected in the form of a HNO3 and a HNO2 to form an enrichment solution;
a chemical conversion unit, interfaced to the nitrate and nitrite enrichment unit and configured for converting the HNO3 to a RONO2, converting the HNO2 to a RNO2, wherein the R is a C1-C20 alkyl group with or without an aryl substituent of 6-12 carbons;
a first gas chromatography separation unit, connected with a chemical conversion unit and configured for separating the RONO2 and the RNO2;
a pyrolysis unit, connected to the first gas chromatography separation unit and configured for pyrolyzing the RONO2 and the RNO2 to obtain pyrolysis gases, respectively containing CO and N2;
a second gas chromatography separation unit, connected with the pyrolysis unit and configured for separating the CO and the N2 in each pyrolysis gas;
and
an isotope ratio mass spectrometry test unit, interfaced with the second gas chromatography separation unit, configured for performing δ18O and δ15N isotope analysis on the CO and the N2.

4 more elements

A method for simultaneous determination nitrogen and oxygen isotope compositions in nitrate and nitrite, wherein the method comprises:

step S1, converting nitrate in a sample to be detected into RONO2, converting nitrite in the sample to be detected into RNO2 to form a solution to be detected, wherein R is a C1-C20 alkyl group with or without an aryl substituent of 6-12 carbons;
and
step S2, determining RONO2 and RNO2 in the solution to be analysed by adopting a gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry coupling technology to perform δ18O and δ15N isotope analysis.

Dependencies are inferred from the claim text.

Facts

Application: 16/768,893Filed 7 Feb 2020
Priority: CN 201911242698.76 Dec 2019
Published: US 2022/0291179 A115 Sep 2022
Granted: 24 Jan 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

G01N 30/7206
Mass spectrometers: interfaced to gas chromatograph
B01D 15/12
Characterised by constructional or operational features: relating to the preparation of the feed
G01N 30/06
Preparation or injection of sample to be analysed: preparation
G01N 30/465
With serial coupling of separation columns: with specially adapted interfaces between the columns