Nitrate Ion Detection Using Hydrogen-Bonding Organic Dopants

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Solution Overview

Problem

Existing ionization sources are not suitable for detecting nitrate ions due to high background nitrate levels, and current methods lack sensitivity in nitrate ion detection.

Innovation Solution

An ion exchange process using a dopant with two or more functional groups capable of simultaneous convergent hydrogen bonding with nitrate ions, forming a negatively charged nitrate-dopant ion analyte that can be detected by spectrometry analysis, involving a gas with both neutral and ionized dopant forms to desorb and replace nitrate ions in a sample.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing ionization sources are used for nitrate ion detection, then the detection process is simple, but the sensitivity is poor due to high background nitrate levels

Engineering Contradiction:
Improvenitrate ion detection sensitivityVSAvoiddetection process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a dopant as an intermediary substance that mediates between the ionization source and nitrate ions. The dopant forms a complex with nitrate ions, enabling selective detection. This intermediary approach allows the detection system to distinguish target nitrate ions from background interference, significantly improving detection sensitivity without requiring complex device modifications

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical parameters of the detection system by introducing a dopant with specific functional groups capable of hydrogen bonding with nitrate ions. This parameter change transforms the interaction mechanism between the ionization source and nitrate ions, enabling selective complex formation that enhances detection sensitivity while maintaining a relatively simple detection process

Inventive Principle:
Principle #35Parameter changes

2Strength

If a dopant with multiple functional groups is used to enhance nitrate ion binding, then the binding energy increases, but the device complexity increases

Engineering Contradiction:
Improvenitrate-dopant binding energyVSAvoiddopant structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent employs a dopant composed of multiple functional groups (such as carbonyl and hydroxyl groups) that work synergistically to bind nitrate ions. This composite molecular structure creates multiple hydrogen bonding interactions simultaneously, significantly enhancing binding energy. The dopant acts as a composite material at the molecular level, where different functional groups contribute to the overall binding strength without requiring complex device structures

Inventive Principle:
Principle #40Composite materials

3Measurement precision

If ion exchange process is implemented to desorb nitrate ions, then the detection sensitivity improves, but the process complexity increases

Engineering Contradiction:
Improvenitrate ion detection sensitivityVSAvoidion exchange process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a preliminary ion exchange process where the dopant is pre-introduced into the ionization source before nitrate ion detection. The dopant undergoes ionization and forms a reactive species that readily exchanges with nitrate ions on the sample surface. This preliminary action prepares the detection system in advance, enabling sensitive detection without requiring complex real-time process control

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The ion exchange process is designed to be self-driven by the chemical affinity between the ionized dopant and nitrate ions. The dopant automatically exchanges ions with the sample surface without requiring external energy input or complex control mechanisms. This self-service characteristic simplifies the overall process while maintaining high detection sensitivity

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method significantly enhances the sensitivity of nitrate ion detection, with dopants like oxalic acid improving the limit of detection by approximately a factor of 20 compared to lactic acid, and demonstrates superior binding energies of nitrate-dopant analyte ions over nitrate-lactate ions.

Implementation Method 1

a dopant with two or more functional groups capable of simultaneous convergent hydrogen bonding with nitrate ions

Methodology Applied
Scientific EffectHydrogen bonding: Chemical Bonding

Implementation Method 2

providing a gas comprising a dopant in both neutral and ionized forms; generating ionized dopant within the ionization source

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 3

contacting a nitrate-containing sample with the gas comprising the dopant and thereby desorbing a nitrate ion from the sample to form a negatively charged nitrate-dopant ion analyte and replacing the desorbed nitrate ion with a negatively charged ionized dopant molecule

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Data Source

PatentEP3289341B1Organic dopants in both neutral and ionized forms for the detection of nitrates
Publication Date: 2024.01.17 SMITHS DETECTION MONTREAL
  • EP3289341B1 patent drawingFigure 1~2
  • EP3289341B1 patent drawingFigure 3

AI summary

The present disclosure relates to an ion exchange process, as well as a process and system for detecting nitrates, which employ a class of dopants comprising at least two functional groups capable of simultaneous convergent hydrogen bonding with a nitrate ion. In an aspect, the present disclosure provides an ion exchange process for forming a negatively charged nitrate-dopant ion analyte for analysis by a spectrometry analysis instrument, comprising: providing a gas comprising a dopant in both neutral and ionized forms; contacting a nitrate-containing sample with the gas comprising the dopant and thereby desorbing a nitrate ion from the sample to form a negatively charged nitrate- dopant ion analyte and replacing the desorbed nitrate ion with a negatively charged ionized dopant molecule; wherein the dopant is an organic compound comprising two or more carbon atoms and two or more functional groups capable of simultaneous convergent hydrogen bonding with a nitrate ion; or the dopant is an organic compound comprising at least two carbon atoms and only a single functional group capable of hydrogen bonding with a nitrate ion, which group is a –COOH functional group, and where the carbon atom of the -COOH functional group is bonded directly to another carbonyl group; and with the proviso that the dopant is not lactic acid, a lactic acid salt or a compound that forms lactate ions upon ionization.