Fast, Accurate Analysis of 28 Elements in Water using ISO Method 17294-2 for ICP-MS

Importance of the Topic

Rapid and accurate multi-element analysis in water is critical for environmental monitoring, regulatory compliance, and pollution source identification. The presence of trace and major elements, including emerging contaminants such as rare earth elements (REEs), requires robust methods to deliver reliable data in diverse matrices.

Aim and Overview of the Study

This study evaluates the performance of the Agilent 7850 ICP-MS following ISO 17294-2 for the determination of 28 elements in natural water, mineral water, and tap water. Key objectives include testing detection limits, interference removal (polyatomic and doubly charged ions), method reproducibility over an eight-hour sequence, and accuracy in certified reference materials (CRMs) with and without REE spikes.

Methodology and Instrumentation Used

Samples and standards were prepared in 1% HNO3 and 0.5% HCl to stabilize elements such as Hg and Ag. Calibration covered trace levels (0.1–100 ppb) and major elements (up to 10,000 ppb). Two CRMs (NIST 1640a and SLRS-6) were analyzed undiluted and at 2× dilution, with matrix spikes to assess accuracy.

• Agilent 7850 ICP-MS with Ultra High Matrix Introduction (UHMI) and ORS 4 collision cell in He mode (standard and enhanced He for Se)
• SPS 4 autosampler, MicroMist nebulizer, Scott-type spray chamber, one-piece quartz torch
• ICP-MS MassHunter Method Wizard for automated method setup and M2+ correction for REE overlaps
• Internal standards: Sc, Ge, Rh, In, Ir, Bi added online

Main Results and Discussion

Detection limits for all elements were well below ISO 17294-2 requirements. As and Se LOQs were 0.018 ppb and 0.055 ppb, respectively. Application of automated M2+ correction recovered As and Se within ±3% despite 100 ppb REE spikes. ISTD recoveries remained within ±20% over eight hours, demonstrating long-term stability. QC checks after every 10 samples met ±10% recovery criteria with no failures. CRM analysis yielded recoveries of 89–108%, and matrix spikes in 2× diluted CRMs showed 91–105% recoveries for all elements.

Benefits and Practical Applications

• Fast method development using Method Wizard and autotune reduces setup time
• Standard He collision mode and M2+ correction avoid reactive gases and complex sample-specific tuning
• High throughput compatible with routine environmental laboratories analyzing hundreds of samples daily
• Robust performance over long sequences minimizes retuning and maintenance downtime
• Accurate monitoring of trace contaminants and emerging REE pollutants in water matrices

Future Trends and Applications

Growth in REE use will drive demand for sensitive interference-free water analysis. Future developments may include advanced reaction cell chemistries, higher matrix tolerance, further automation of sample handling and data processing, and integration with artificial intelligence for predictive environmental risk assessment.

Conclusion

The Agilent 7850 ICP-MS, operated in He collision mode with automated M2+ correction, provides a rapid, accurate, and reproducible workflow for 28-element analysis in water. The method meets strict ISO 17294-2 criteria for detection limits, interference control, and long-term stability, making it highly suitable for routine environmental monitoring and quality assurance laboratories.

Reference

• ISO 17294-1:2004 Water quality—Application of inductively coupled plasma mass spectrometry (ICP-MS) —Part 1: General guidelines
• ISO 17294-2:2016 Water quality—Application of inductively coupled plasma mass spectrometry (ICP-MS) —Part 2: Determination of selected elements including uranium isotopes