Analysis of drinking water in compliance with the U.S. EPA Method 200.8, Revision 5.4 using the Thermo Scientific iCAP MSX ICP-MS

Significance of the Topic

Routine determination of trace elements in drinking water is critical to ensure public health and regulatory compliance. The U.S. EPA Method 200.8 defines stringent detection limits and quality control criteria for inorganic contaminants. Employing robust analytical procedures supports accurate monitoring of surface water, groundwater and treated water and safeguards against chemical hazards.

Objectives and Study Overview

This study evaluated the analytical performance of the Thermo Scientific iCAP MSX ICP-MS configured according to EPA Method 200.8 Revision 5.4. The objective was to demonstrate precise, accurate and continuous analysis of diverse water matrices—including tap water, ground water and surface water—over extended runs with minimal downtime and full compliance with drinking water regulations.

Methodology and Instrumentation

• Instrumentation: Thermo Scientific iCAP MSX ICP-MS with integrated Argon Gas Dilution (AGD) system, cyclonic spray chamber and Ni-tipped cones, coupled to an iSC-65 autosampler
• Sample introduction: 1% nitric acid acidified samples, online argon dilution (AGD level 5) to manage total dissolved solids (TDS)
• Operating conditions: RF power 1550 W, cool gas flow 14 L/min, nebulizer flow 0.447 L/min, sampling depth 8 mm, no collision/reaction cell
• Data acquisition: Qtegra ISDS Software autoparameter tuning and template-based workflows for reproducible control, calibration and QC reporting

Key Results and Discussion

• Detection limits (MDLs) for 21 analytes were below regulatory Maximum Contaminant Levels (MCLs), with MDLs in the low micrograms per liter range and correlation coefficients above 0.999 in calibration curves.
• Internal standards (6Li, Sc, Y, Tb, Bi) maintained recoveries within 80–112% over 16 hours, confirming instrumental robustness and effective matrix dilution.
• Laboratory fortified blanks and matrix spikes delivered recoveries between 85–115%, while duplicate precision showed <5% variability, meeting EPA acceptance criteria.
• Analysis of SLRS-5 certified reference material three times during the run produced recoveries within 86–112%, validating the accuracy across diverse analytes and concentrations.

Benefits and Practical Applications

The iCAP MSX ICP-MS workflow allows uninterrupted, high-throughput analysis of drinking water and environmental samples with varying TDS levels. Automated AGD minimizes cone fouling and maintenance, while software-driven QC ensures regulatory compliance. This enhances laboratory efficiency in water quality monitoring programs, QA/QC testing and environmental surveillance.

Future Trends and Opportunities

• Further integration of automated matrix recognition and adaptive dilution strategies to expand analysis to challenging matrices such as seawater and industrial effluents.
• Development of real-time data analytics and cloud-based reporting for remote monitoring and decision support in water utilities.
• Coupling ICP-MS with speciation techniques (e.g., HPLC-ICP-MS) for comprehensive assessment of element bioavailability and toxicity.
• Implementation of miniaturized and field-deployable ICP-MS configurations for on-site water quality screening.

Conclusion

The study demonstrates that the Thermo Scientific iCAP MSX ICP-MS, equipped with controlled argon gas dilution and advanced software, reliably meets U.S. EPA Method 200.8 requirements. The method delivers sensitive, accurate and precise quantification of trace elements in diverse water samples, supporting robust drinking water compliance monitoring with minimal downtime and streamlined QC management.

References

• U.S. EPA Method 200.8 Revision 5.4 U.S. Environmental Protection Agency, 1994
• U.S. EPA National Primary Drinking Water Regulations, 40 CFR Part 141
• U.S. EPA Secondary Drinking Water Standards and Guidance for Nuisance Chemicals