Analysis of Undiluted Seawater using ICP-MS with Ultra High Matrix Introduction and Discrete Sampling

Significance of the Topic

Monitoring trace elements in seawater is critical for assessing marine pollution and achieving UN Sustainable Development Goal 14.1 on ocean conservation. Accurate multielement analysis supports environmental protection, industrial compliance, and research.

Objectives and Study Overview

This study demonstrates the direct measurement of undiluted seawater using the Agilent 7850 ICP MS equipped with Ultra High Matrix Introduction and the ISIS 3 discrete sampling system. It aims to achieve accurate, stable, low-level detection of a broad range of elements with minimal sample preparation.

Methodology and Instrumentation

Samples and standards were prepared in 1 percent HNO3 and 0.5 percent HCl. Calibration used six-point curves and quality control included matrix spikes. Key instrumental features include

• Agilent 7850 ICP MS with ORS4 collision reaction cell in no-gas, helium, enhanced helium and hydrogen modes
• Ultra High Matrix Introduction aerosol dilution at level 8 to maintain plasma robustness
• ISIS 3 discrete sampling to reduce analysis time and carryover
• Online internal standard addition via a dedicated port

Key Results and Discussion

Method detection limits for trace analytes were typically in the low nanogram per liter range. Calibration linearity exceeded R of 0.9999 across 0.1 ppb to 100 ppm. Certified reference materials and spike recoveries for most elements were within plus or minus ten percent. Internal standard recoveries remained stable over seven hours, confirming robust plasma conditions and effective matrix tolerance.

Benefits and Practical Applications

This workflow enables high-throughput direct analysis of seawater without dilution or pre-treatment, reducing contamination risk and labor. Automated tuning, maintenance alerts, and IntelliQuant semi-quantitative screening enhance lab efficiency and data reliability.

Future Trends and Potential Applications

Emerging developments may include advanced cell gas chemistries for further interference removal, integrated automation for real-time environmental monitoring, and expanded screening of emerging contaminants at sub-ppt levels.

Conclusion

The Agilent 7850 ICP MS with UHMI and ISIS 3 provides accurate, stable, and efficient analysis of undiluted seawater, supporting environmental monitoring and research demands.

References

1. United Nations Sustainable Development Goals
2. Kubota et al Routine Analysis of Soils using ICP-MS
3. Kubota and Yan China Soil Pollution Survey
4. Kubota Simple Soil Analysis with 7800 ICP-MS
5. Yamanaka and Wilbur High Matrix Analysis with 7900 ICP-MS
6. Leonhard et al J Anal At Spectrom 2002
7. Fletcher and Woods Direct Seawater Analysis with 7800 ICP-MS
8. Agilent Performance of 7900 ICP-MS with UHMI
9. Agilent Plasma Robustness and Matrix Tolerance
10. NMIA MX014 Certificate of Analysis
11. Agilent Enhanced Helium Collision Mode
12. Agilent IntelliQuant for ICP-MS
13. Agilent Smart Self-Health Checks for ICP-MS