Analysis of Drinking Water by U.S. EPA Method 200.8 Using ICPMS-2040 with Collision Cell

Significance of the Topic

Trace element analysis in drinking water is essential for safeguarding public health and meeting regulatory standards. EPA Method 200.8 provides a standardized ICP-MS approach to monitor elemental contaminants at trace levels.

Objectives and Study Overview

This study assessed the performance of the Shimadzu ICPMS-2040 system for quantifying trace elements in drinking water and a certified reference material (CRM JSAC 0302-4a) following U.S. EPA Method 200.8 guidelines. Key aims included accuracy evaluation, interference removal, spike recovery, and long-term stability.

Methodology

- Sample Preparation:

• Drinking water samples acidified with 1 % HNO3 and spiked with 100 µg/L Au to stabilize mercury.
• CRM JSAC 0302-4a used for accuracy assessment.

- Calibration and Standards:

• Five-point calibration (STD1–STD5) covering major and trace elements as specified in EPA 200.8.
• Internal standards: Li, Sc, Ga, Y, Rh, In, Tb, Ho, Lu, Bi at 1000 µg/L and Au at 100 µg/L added online.

- Interference Removal:

• Helium collision mode applied to minimize polyatomic interferences such as 44Ca16O+ on 60Ni.

- Detection Limits:

• Instrument Detection Limits (IDLs) and Method Detection Limits (MDLs) determined per EPA 200.8 procedures.
• IDL = 3×σ(blank)/slope; MDL = t×σ(spiked blank)/slope at 99 % confidence.

Instrumentation

• ICPMS-2040 system
• Nebulizer DC04
• Cyclone spray chamber
• Mini-torch for reduced argon consumption
• Nickel skimmer cone
• AS-20 autosampler with online internal standard kit
• Operating conditions: RF power 1.20 kW; plasma gas 9.0 L/min; auxiliary gas 1.10 L/min; carrier gas 0.45 L/min; dilution gas 0.40 L/min; He collision gas.

Main Results and Discussion

• CRM recoveries ranged from 98 % to 107 %, meeting EPA QC criteria of 90–110 %
• Spike recoveries in drinking water fell within 94 %–107 %, satisfying EPA 200.8 requirement of 70–130 %
• CCV recoveries over seven hours remained within 90–110 %, indicating calibration stability
• Internal standard recoveries stayed between 60 % and 125 %, demonstrating consistent instrument performance.

Benefits and Practical Applications

The ICPMS-2040 delivers high accuracy and stability for trace element analysis while reducing argon gas usage and operational costs via a mini-torch design. Preset method templates streamline setup, facilitating routine monitoring in environmental and quality control laboratories.

Future Trends and Applications

Advances may include enhanced reaction cell chemistries for broader interference removal, integration with automation and laboratory information management systems, portable ICP-MS platforms for field analysis, and AI-driven data processing to improve throughput and decision-making.

Conclusion

The ICPMS-2040 effectively meets EPA Method 200.8 requirements for drinking water analysis, demonstrating accurate quantification, robust interference management, and stable operation over extended runs with reduced resource consumption.

References

• EPA Method 200.8 Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma–Mass Spectrometry Revision 5.4
• Shimadzu Application News 01-00573_EN Analysis of Drinking Water by U.S. EPA Method 200.8 Using ICPMS-2050 with Collision/Reaction Cell.