Determination of Mineral and Trace Elemental Contents in Drinking Water by Inductively Coupled Plasma Mass Spectrometry

Significance of the Topic

Fresh drinking water purity is critical for human health as excess heavy metals pose acute or chronic risks. Inductively coupled plasma mass spectrometry offers multielement detection with high sensitivity and dynamic range, making it essential for monitoring water quality and ensuring safety.

Objectives and Study Overview

This application describes a rapid method employing Shimadzu ICPMS-2030 with helium collision cell technology to determine twenty four trace and mineral elements in drinking water samples. Results from tap, filtered and bottled water were compared with US EPA guidelines to assess compliance.

Methodology and Instrumentation

Samples of tap water, filtered water and bottled water were diluted twofold with 1 percent ultrapure nitric acid. An additional 0.5 percent hydrochloric acid step and extra washes were applied for mercury stabilization and carryover elimination. Calibration used multi element standards prepared in 1 percent nitric acid with Bi Ho In Rh and Sc as internal standards. Helium collision cell mode minimized polyatomic interferences.

Instrumentation

Analysis was carried out on a Shimadzu ICPMS-2030 coupled to an AS-10 autosampler. Collision cell technology utilized helium at 6 milliliters per minute. Key parameters included 1.20 kilowatt RF power, argon plasma gas at 8.0 L/min, auxiliary gas at 1.10 L/min, carrier gas at 0.70 L/min, Mini-Torch, 07UES nebulizer, cyclone chamber at 5 °C and ten scans per sample.

Main Results and Discussion

All measured element concentrations in water samples were below the maximum contaminant levels set by US EPA. Tap water showed the highest mineral levels while bottled water had negligible detectable metals. Filtration did not consistently reduce heavy metal concentrations. Arsenic, cadmium, lead and mercury remained at sub microgram per liter levels. Calibration curves exhibited correlation coefficients above 0.9994 and method detection limits at sub-ppb levels. Spike recovery ranged from 90 to 118 percent with relative standard deviation below 3 percent for most elements. Stability tests over five hours yielded recoveries within 80 to 120 percent and internal standard drift under 15 percent.

Benefits and Practical Applications

This validated ICPMS method provides a fast reliable tool for routine water quality monitoring, supporting regulatory compliance and health risk assessment. It enables simultaneous quantification of multiple elements with high throughput and minimal sample preparation.

Future Trends and Potential Applications

• Integration with chromatography for speciation analysis
• Development of portable ICPMS platforms for field monitoring
• Automation and real time process control in water treatment
• Advanced data analytics and machine learning for trend prediction

Conclusion

The described high throughput ICPMS approach achieves sensitive accurate stable analysis of trace and mineral elements in drinking water well below regulatory limits. It is a valuable technique for routine QA QC and environmental monitoring.

References

1. Strategy for water analysis using ICP MS J L Fernandez Turiel Fresenius J Anal Chem 2000 368 601 606
2. US Environmental Protection Agency National Primary Drinking Water Regulations 2018
3. US EPA Method 200.8 Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma Mass Spectrometry Revision 5.4 1994