Duplex Inductively-Coupled Plasma Torch for Simultaneous Gas and Liquid Analysis

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Solution Overview

Problem

Conventional inductively-coupled plasma torches face challenges in accurately introducing gaseous samples from gas chromatographs into the center of the plasma, leading to reduced sensitivity and accuracy, and require torch replacement for switching between gaseous and solution samples, necessitating multiple plasma mass spectrometers for analysis.

Innovation Solution

A duplex structure inductively-coupled plasma torch with an inner injector tube for gaseous samples and an outer injector tube for solution or dry aerosol samples, allowing for coaxial integration and simultaneous analysis without replacing the capillary tube or make-up gas tube, utilizing a capillary tube within the inner injector tube for gaseous samples and a branch tube for aerosol samples.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single injector tube is used for both gaseous and solution samples, then device complexity is reduced, but it becomes impossible to introduce both sample types into the center of plasma simultaneously

Engineering Contradiction:

Improvetorch structureVSAvoidsample introduction capability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The injector tube is divided into two separate coaxial tubes: an inner injector tube for gaseous samples and an outer injector tube for solution samples. This segmentation allows each tube to be optimized for its specific sample type while maintaining the ability to introduce both samples into the plasma center simultaneously through the same torch assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner injector tube is nested within the outer injector tube in a coaxial arrangement. The inner tube carries gaseous samples through its central capillary, while the outer tube carries solution samples through its annular space. Both sample streams are introduced into the plasma center simultaneously without interference, enabling multi-functionality within a single torch structure.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Adaptability or versatility

If the capillary tube is removed for solution analysis, then solution samples can be introduced, but GC analysis capability is lost and torch replacement is required

Engineering Contradiction:

Improvesample type flexibilityVSAvoidtorch replacement time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The dual-tube injector structure enables the same torch to perform both GC analysis and solution analysis without requiring physical replacement of components. The inner tube handles gaseous samples from GC, while the outer tube handles atomized solution samples, making the torch universally applicable to multiple analysis modes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Both the inner and outer injector tubes are pre-configured and integrated into the torch assembly before use. The capillary tube within the inner tube and the nebulizer connection to the outer tube are arranged in advance, allowing immediate switching between sample types without disassembly or reconfiguration.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If gaseous molecules are introduced off-center into plasma, then the torch structure is simpler, but sensitivity and analysis accuracy deteriorate

Engineering Contradiction:

Improvesample introduction systemVSAvoidanalysis accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The inner injector tube is positioned coaxially within the outer injector tube, with both tubes aligned to introduce samples precisely at the center of the plasma. This localized coaxial arrangement ensures that gaseous molecules from the inner tube and solution aerosols from the outer tube both reach the high-temperature plasma center, maximizing ionization efficiency and analytical sensitivity.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7572999B2Inductively-coupled plasma torch for simultaneous introduction of gaseous and liquid samples

Publication Date: 2009.08.11 AGILENT TECHNOLOGIES INC

AI summary

To provide an inductively-coupled plasma torch capable of realizing a GC analysis or the like and a solution analysis by the same torch without removing a capillary tube, etc. The injector tube of the inductively-coupled plasma torch includes an outer injector tube 11 for introducing an atomized solution sample or the like into the inductively-coupled plasma, and an inner injector tube 12 for introducing gaseous molecules into the inductively-coupled plasma, housed in the outer injector tube as integrated and coaxially with it. The inner injector tube is able to convey make-up gas, and has a capillary tube 4 for conveying gaseous molecules and carrier gas together. For sample introduction in analyzing a gaseous sample, the inner injector tube 12 is used, and for sample introduction in analyzing an aerosol sample, the outer injector tube 11 is used.