Accurate Elemental Analysis of Drinking Water per Bureau of Indian Standards by ICP-MS

Importance of Topic

The safety of drinking water is fundamental to public health, as water sources can be impacted by pollutants from industrial, agricultural, and natural origins. Regulations such as the Bureau of Indian Standards (BIS) 10500, 13428, and 14543 mandate strict limits for toxic elements including heavy metals and uranium. Reliable analytical methods are therefore essential to ensure compliance and protect consumers.

Study Objectives and Overview

The study aimed to develop and validate a fast, simple, and compliant method for the simultaneous determination of 26 elements in various drinking water samples according to the latest BIS standards. Using the Agilent 7850 ICP-MS and SPS 4 autosampler, the method assesses elemental concentrations in bottled drinking water, bottled natural mineral water, and municipal tap water in a single run.

Methodology and Instrumentation

Sample preparation involved acidifying water samples and calibration standards with 1% HNO3 and 0.5% HCl, followed by a 1.25x dilution. NIST SRM 1643f was used for accuracy verification, and internal standards (Rh, Sc, Ge, Lu, Bi, Au) were added online.

• Instrument: Agilent 7850 ICP-MS with SPS 4 autosampler
• Sample introduction: MicroMist nebulizer, Scott spray chamber, quartz torch
• Interface: Nickel sampling and skimmer cones
• Gas mode: Octopole Reaction System (ORS4) in helium kinetic energy discrimination (He KED) mode
• UHMI aerosol dilution enhances robustness for high dissolved solids
• Software: Agilent ICP-MS MassHunter with low-matrix preset method and autotune

Main Results and Discussion

Detection limits for all 26 elements were well below the maximum permissible limits defined by BIS, confirming method sensitivity. Repeatability studies in three water types showed relative standard deviations below 5% for most elements. NIST 1643f SRM recoveries ranged between 96% and 104%, demonstrating accuracy. Quality control checks before and after a six-hour run exhibited drift under 5%, and internal standard recoveries remained within ±20% over 130 analyses, indicating method robustness and stability without maintenance.

Benefits and Practical Applications of the Method

• Simultaneous multi-element analysis, including uranium, in a single run
• High sensitivity and low detection limits for trace contaminants
• Rapid throughput with minimal setup and maintenance requirements
• Full compliance with BIS regulatory standards for drinking water
• Robust performance over extended analysis sequences

Future Trends and Potential Applications

The approach can be extended to other environmental matrices such as wastewater, soils, and sediments using UHMI technology. Future developments may include greater automation of sample preparation, integration with data analytics for real-time monitoring, and adaptation of the method for emerging contaminants beyond regulated elements.

Conclusion

The Agilent 7850 ICP-MS method provides a reliable, accurate, and efficient solution for the analysis of 26 elements in drinking water, fully meeting BIS requirements. Its robust performance and streamlined workflow support high-throughput testing in quality assurance and regulatory laboratories.

References

• Bureau of Indian Standards. BIS 10500:2012, BIS 13428:2024, BIS 14543:2024.
• Agilent Technologies. Octopole Collision/Reaction Cell and Helium mode technology brief, 5994-1172EN.
• Dong S., Nelson J., Yamanaka M. Routine Analysis of Fortified Foods using the Agilent 7800 ICP-MS, publication 5994-0842EN.
• Agilent Technologies. Successful Low Level Mercury Analysis using Agilent ICP-MS, publication 5990-7173EN.