Inline Dilution Valve for ICP-MS Speciation Analysis
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Solution Overview
Problem
ICP-MS instruments struggle to distinguish between different species of chemical elements due to species interconversion during manual pre-dilution, leading to erroneous analysis, and existing HPLC systems pose contamination risks with metal components.
Innovation Solution
A system with inline and automatic dilution capabilities using a valve system and syringe pumps for real-time speciation analysis, avoiding metal components to prevent contamination and allowing post-column dilution for favorable separation conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If manual pre-dilution is performed, then sample concentration is reduced for analysis, but species interconversion occurs leading to erroneous analysis
Solution Approach 1:
The system performs separation of chemical species before dilution, ensuring that species interconversion is prevented. The HPLC separation occurs first, isolating different species in distinct chromatographic peaks, and only then is the separated analyte introduced to the ICP-MS for detection. This preliminary separation action eliminates the species interconversion problem that would occur with manual pre-dilution.
Solution Approach 2:
The patent extracts the dilution step from the pre-analysis phase and moves it to post-separation phase. By taking out the dilution operation and performing it after HPLC separation, the system avoids species interconversion while still achieving the necessary concentration reduction for ICP-MS analysis. The separated species are individually diluted without risk of interconversion.
2Adaptability or versatility
If HPLC systems with metal components are used, then speciation analysis is enabled, but contamination risks increase
Solution Approach 1:
The patent extracts and removes metal components from the HPLC system by using a non-metallic column material (e.g., polymer-based stationary phase). This extraction of harmful metal elements eliminates the contamination source while preserving the speciation analysis capability. The non-metallic column separates species without introducing metallic contamination to the sample.
Solution Approach 2:
The system creates an inert, non-metallic environment throughout the HPLC-ICP-MS interface by using non-metallic tubing, fittings, and column materials. This inert environment prevents metallic contamination from leaching into the sample stream, ensuring that trace metal analysis is not compromised by system contamination.
3Ease of operation
If dilution is performed before separation, then sample preparation is simplified, but species interconversion occurs during dilution
Solution Approach 1:
The system performs separation before dilution, reversing the conventional order. By separating species through HPLC first and then diluting the separated analyte, the system maintains species composition stability throughout the process. The separated species are stable during dilution because they are already isolated in distinct chromatographic peaks, eliminating interconversion risks.
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 and precise speciation analysis by preventing species interconversion and eliminating metallic contamination, providing stable retention times and high accuracy across various matrices.
Implementation Method 1
A syringe pump is operably coupled to the valve system and is configured to deliver the diluent and the sample
Implementation Method 2
The valve system and the syringe pump are configured to perform automated dilution sequences
Implementation Method 3
ICP spectrometry employs electromagnetically generated partially ionized argon plasma which reaches a temperature of approximately 7,000K. When a sample is introduced to the plasma, the high temperature causes sample atoms to become ionized or emit light.
Implementation Method 4
ICP spectrometry employs electromagnetically generated partially ionized argon plasma
Implementation Method 5
a sample introduction system may withdraw an aliquot of a liquid sample from a container and thereafter transport the aliquot to a nebulizer that converts the aliquot into a polydisperse aerosol suitable for ionization in plasma
Implementation Method 6
The aerosol is then sorted in a spray chamber to remove the larger aerosol particles
Implementation Method 7
measuring the spectra of the emitted mass or light allows the determination of the elemental composition of the original sample
Data Source
AI summary
Systems and methods for speciation of chemicals of interest with inline and automatic dilution or addition of other fluids prior to or following speciation with subsequent analysis by ICP instruments are described. A system embodiment includes, but is not limited to, a first valve having a first valve configuration to receive a sample into a holding loop coupled to the first valve and a second valve configuration to transfer the sample from the holding loop; and a second valve having a first valve configuration configured to receive the sample from the first valve and direct the sample to a speciation column to separate one or more species of the sample, the second valve further including a fluid addition port configured to receive a fluid into the second valve to mix with the sample after the sample exits the speciation column.