LA-ICP-MS Quantification Using Low-Flow Standard Addition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for quantitative analysis of elements in a sample gas using LA-ICP-MS face challenges due to the lack of solid reference samples, variations in plasma conditions, and difficulties in accurately measuring elements with varying sensitivities, especially when using TOF-ICP-MS and electric reheating furnaces.
Innovation Solution
A method that introduces a standard solution containing specific elements in known concentrations directly to the nebulizer at a low flow rate, allowing for a quantitative analysis without a solid reference sample, by calculating instrument background and sample-gas signal intensities to determine accurate concentrations of elements in the sample gas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a solid reference sample is used for quantitative analysis, then the analysis can be performed with existing methods, but accurate quantification is difficult due to differences in components between sample and reference sample causing different particle emission amounts
Solution Approach 1:
The invention uses a standard solution containing elements in known concentrations as a reference, which is then vaporized and introduced to the ICP-MS. This creates a virtual copy of the elemental composition that can be compared against the sample gas, eliminating the need for physical solid reference samples with matching compositions.
Solution Approach 2:
The invention changes the physical state of the reference material from solid to solution, and then vaporizes it to introduce as gas to the ICP-MS. This parameter change allows the reference material to be introduced in a form that matches the sample introduction method, enabling direct comparison without composition-matching constraints.
2Measurement precision
If separate operations are used for sample gas introduction and standard solution introduction, then each can be optimized independently, but plasma conditions differ between introductions causing non-constant response factors
Solution Approach 1:
The invention merges the sample gas introduction path and the standard solution vaporization path into a single combined introduction system. Both the sample gas from laser ablation and the vaporized standard solution are introduced through the same gasified sample introduction part to the torch, ensuring identical plasma conditions for both measurements.
Solution Approach 2:
The gasified sample introduction part acts as an intermediary that receives both the sample gas and the vaporized standard solution, and delivers them to the torch under controlled conditions. This intermediary ensures that both materials experience the same transport and plasma generation conditions, making the response factors constant.
3Productivity
If TOF-ICP-MS is used for simultaneous multi-element analysis, then all elements can be analyzed at once, but detection sensitivity is lower making fine particle analysis difficult
Solution Approach 1:
The invention uses a quadrupole ICP-MS with dynamic switching between standard solution introduction and sample gas analysis. The system dynamically changes the introduction source (standard solution or sample gas) while maintaining high detection sensitivity, achieving both accurate quantification and efficient analysis.
4Quantity of substance
If electric reheating furnace is used to vaporize standard solution, then elements can be introduced to ICP-MS, but argon gas expansion at high temperature changes detection sensitivities
Solution Approach 1:
The invention changes the temperature parameter from high temperature (several thousands of degrees) to a moderate temperature (100-400°C) for vaporizing the standard solution. This parameter change prevents argon gas expansion while still achieving complete vaporization of the standard solution, maintaining detection sensitivity stability.
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
Enables accurate quantitative analysis of elements in a sample gas without using a solid reference sample, correcting for sensitivity changes, and ensuring precise measurement of elements in the sample gas.
Implementation Method 1
a laser ablation device irradiating a solid sample as the measurement target with laser light to evaporate and atomize the solid sample
Implementation Method 2
a torch part forming plasma to ionize the sample
Implementation Method 3
a mass spectrometry part separating the ion, and a detection part detecting the separated ion
Data Source
AI summary
The present invention provides a method for a quantitative analysis of elements in a sample gas, such as an LA-ICP-MS, without use of a solid reference sample. The present invention includes, in a method for a quantitative analysis of elements in a solid sample with an inductively coupled plasma mass spectrometer to which a sample gas generated from the solid sample is introduced, measuring concentrations of elements contained in the sample gas by use of signal intensities obtained by introducing a standard solution containing specific elements in known concentrations from a solution introduction unit to a torch part in such a manner as to directly supply (standard addition) the standard solution at a flow rate of 3 μL/min or less.