WPC: Novel developments in ICP-MS: How can the analysis of complex samples be made simple?

Importance of the Topic

ICP-MS has become an essential tool for quantifying trace elements in diverse and complex sample matrices. Its evolution from specialized research instruments to widely adopted analytical workhorses reflects its value in environmental, industrial and regulatory applications. Recent challenges such as high dissolved solid content and matrix interferences demand novel solutions to simplify analysis and maintain data quality.

Objectives and Study Overview

This study demonstrates advances in ICP-MS technology using the Thermo Scientific iCAP RQplus to enable straightforward analysis of soils, waters and high salt brines. Key goals include validating method performance across standard reference materials and real samples, evaluating automated argon dilution modes and assessing long term stability over extended measurement periods.

Methodology and Instrumentation

Sample preparation and instrument setup included

• Soil digestion by microwave assisted aqua regia following EPA Method 6020B
• Analysis of wastewater, brackish and groundwater samples as technical replicates
• Preparation of brine solutions at 0.5 to 25 percent w w NaCl in nitric acid
• Thermo Scientific iCAP RQplus ICP-MS with iSC 65 autosampler
• PFA microflow nebulizer and humidifier for high TDS matrices
• Automated argon gas dilution (AGD low mid high) via Qtegra ISDS software
• Collision cell operated in KED mode with kinetic energy barrier gas

Main Results and Discussion

Major findings include

• Certified recoveries of NIST SRM soils within 90 to 110 percent
• Stable internal standard signals with minimal suppression except for tellurium under high salt conditions
• Automated AGD allowed direct analysis of brine up to 25 percent w w NaCl eliminating manual dilution
• Oxide formation rates below 0.5 percent under optimized gas flows
• Consistent calibration verification over batches of 120 samples maintained accuracy and precision

Benefits and Practical Applications

The enhanced ICP-MS workflow offers

• Robust tolerance to high matrix loads with reduced maintenance
• Increased throughput by automating dilution and minimizing sample handling
• Improved detection limits and data reliability for environmental and industrial testing

Future Trends and Applications

Emerging directions include

• Further automation of sample introduction and matrix removal
• Integration of separation techniques for direct solid sampling
• Advanced software tools for method development and quality control

Conclusion

Innovations such as automated argon dilution and specialized sample introduction in the iCAP RQplus simplify the analysis of complex and high TDS matrices. These developments enhance robustness, maintain accuracy and support high throughput needs in modern analytical laboratories.

References

1. Application Note 1592 Robust analysis of a variety of water and wastewater samples according to EPA Method 6020B SW 846 Thermo Fisher Scientific
2. Application Note 1835 Accurate and robust analysis of challenging environmental samples for regulatory compliance Thermo Fisher Scientific
3. Application Note 1503 Managing the challenges of analyzing brine solutions using ICP MS with argon gas dilution Thermo Fisher Scientific