Hybrid Ion Source Segmentation for ESI-APCI Voltage Interference

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Solution Overview

Problem

Conventional hybrid ion sources that combine electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) suffer from low ion intensity due to adverse effects between high voltages and mutual electric field influences, limiting their ability to achieve high sensitivity and robustness for simultaneous operation of both ionization schemes.

Innovation Solution

A hybrid ion source design with an orthogonal positional relationship between ESI and APCI ion sources, featuring a first aperture electrode opposed to the APCI ion source and an exhaust pump generating airflow from the ESI ionization area to the APCI corona discharge area, which reduces mutual voltage influences and enhances ion introduction efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If ESI and APCI ion sources are disposed in the same space with simultaneous ionization, then the versatility and application range are expanded, but the ion intensity is lowered due to mutual adverse effects between high voltages

Engineering Contradiction:
Improveionization scheme versatilityVSAvoidion intensity
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The ion source is divided into two separate ionization chambers (ESI ionization chamber and APCI ionization chamber) that are physically isolated from each other. Each chamber operates independently with its own ion source, eliminating mutual voltage interference while maintaining the ability to perform both ESI and APCI ionization schemes. The chambers share common components (mass analyzer, detector) to preserve versatility.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If shield electrode is disposed between ESI and APCI to suppress electric field influences, then the mutual voltage interference is reduced, but the sample gas flow is physically separated and ion intensity is lowered

Engineering Contradiction:
Improveelectric field interferenceVSAvoidion intensity
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

Instead of using a shield electrode that blocks gas flow, the system segments the ionization process into two separate chambers. Each chamber maintains its own optimized gas flow path to the common interface, ensuring that sample gas reaches both ion sources without being blocked by shielding structures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design transitions from a two-dimensional planar arrangement where shielding is necessary to a three-dimensional configuration with separate ionization chambers. This spatial reorganization allows independent gas flow paths while maintaining physical separation of electric fields, eliminating the need for shielding electrodes that would block flow.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If high voltage is applied to both electrostatic spray and needle electrode simultaneously, then both ionization schemes operate concurrently, but the ion intensity is mutually lowered due to adverse voltage effects

Engineering Contradiction:
Improvesimultaneous ionization capabilityVSAvoidion intensity
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The ion source is segmented into separate ionization chambers, each housing one ion source type. This physical segmentation allows both ESI and APCI to operate simultaneously at their optimal voltages without mutual interference, as each chamber's electric field is confined to its own space while both ion streams converge at the common interface.

Inventive Principle:
Principle #1Segmentation

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

This configuration achieves high sensitivity and robustness, allowing for simultaneous operation of ESI and APCI with improved ion intensity and reduced noise ion generation, enabling effective analysis of various samples.

Implementation Method 1

an exhaust pump is disposed at the APCI ion source so as to generate an air flow from the ESI ionization area to a corona discharge area

Methodology Applied
Scientific EffectAirflow generation:

Implementation Method 2

The ESI is a technique of passing a sample solution through a capillary, to which high voltage is applied, for spraying to generate charged droplets

Methodology Applied
Scientific EffectElectrospray ionization: Electrohydrodynamics

Implementation Method 3

The APCI is a technique of heating a sample solution for vaporization, and ionizing the obtained solvent molecules through corona discharge

Methodology Applied
Scientific EffectCorona discharge: Corona Discharge

Data Source

PatentEP2927930B8Hybrid ion source, mass spectrometer, and ion mobility device
Publication Date: 2019.08.21 HITACHI HIGH TECH CORP

AI summary

Provided is an ion source achieving high sensitivity and high robustness while executing a plurality of types of ionization schemes. To this end, a hybrid ion source (1) includes: a chamber (24); a first ion source (2) to spray a sample solution (5) for ionization; a second ion source (3) to ionize droplets and/or a gas component sprayed from the first ion source (2); a first electrode (11) to introduce a first ion (7) generated by the first ion source (2), and a second ion generated by the second ion source (3); and an exhaust pump (27) that generates air flow (26) in a direction from a first space area (23) where the first ion (7) is generated to a second space area (19) in the second ion source (3) where the second ion is generated.