Agilent ICP-MS Journal (May 2011 – Issue 46)

Significance of the Topic

Industrial wastewater monitoring and elemental speciation are critical for environmental compliance and public health. Advances in ICP-MS techniques, collision/reaction cell technology, high-matrix introduction, and novel nebulizers enable trace-level quantification, faster throughput, and improved robustness for challenging matrices such as flue gas desulfurization effluent, complex clinical samples, and high-purity acids.

Objectives and Issue Overview

Issue 46 of the Agilent ICP-MS Journal (May 2011) gathers contributions on four key topics:

• High-throughput ICP-MS analysis of flue gas wastewater for U.S. EPA compliance.
• Compound-independent calibration (CIC) applied to arsenic speciation by LC-ICP-MS.
• Design evolution of PFA micro-concentric nebulizers for enhanced sensitivity and clog resistance.
• User experiences and community events showcasing Agilent GC-ICP-MS, ICP-MS installations, and speciation handbook contributions.

Used Instrumentation

• Agilent 7700x ICP-MS with High Matrix Introduction (HMI) and helium collision mode.
• ISIS-DS discrete sampling system for high throughput sequences.
• Agilent 1260 HPLC with arsenic speciation column and guard column.
• Savillex C-Flow PFA micro-concentric nebulizers (50 and 200 μL/min versions).
• Agilent GC-ICP-MS interface hardware and MassHunter Workstation software.

Methodology and Instrumentation

• Flue gas wastewater method: An 89-sample sequence incorporating EPA-mandated blanks, calibration checks (ICV, CCV), laboratory fortified matrix blanks, and matrix interference checks using simulated FGD matrices. HMI and helium mode removed polyatomic interferences, while ISIS-DS enabled rapid discrete sampling.
• Arsenic speciation: LC-ICP-MS separation of AB, MMA, As(III), DMA and As(V) using a 4.6×250 mm column, 2.0 mM PBS/EDTA mobile phase at pH 11.0, with both compound-specific and CIC quantitation based on an As(V) standard.
• PFA nebulizer design: Concentric capillary support within the tip yields prefilming and fine aerosol (~9 μm) with reduced clogging risk at low flow rates (50–200 μL/min).

Main Findings and Discussion

• Flue Gas Wastewater: All QC recoveries remained within ±15% over 89 analyses; matrix spike recoveries averaged 86–120% for 14 elements, demonstrating robust detection at low ppb levels in high TDS matrices.
• Arsenic Speciation: CIC quantitation matched compound-specific calibration within 10% for major As species across 12 undiluted urine samples over a 13 h run, confirming CIC’s suitability when standards are limited.
• Nebulizer Performance: The C-Flow nebulizers delivered high sensitivity, reproducible aspiration rates (±15%), and reliable operation even with high-matrix samples and fine flow control, reducing plasma loading.
• Community Engagement: Over 190 attendees at Agilent user events; Agilent quad ICP-MS systems were used in 47% of research posters at WPC 2011, illustrating broad adoption.

Benefits and Practical Applications

• Regulatory Compliance: Rapid, high-throughput wastewater screening for U.S. EPA guidelines using robust QC protocols.
• Speciation Flexibility: CIC reduces reliance on multiple pure standards and supports unknown peak quantitation in clinical and environmental samples.
• Enhanced Throughput: Discrete sampling and optimized nebulizers accelerate long sequences with minimal drift and superior washout.
• Expanded Applicability: PFA nebulizers compatible with HF-containing solutions and ultra-low volume clinical assays.

Future Trends and Opportunities

Integration of novel sample introduction systems (e.g., microdroplet generators), enhanced collision/reaction cell chemistries, and advanced data analysis (profiling software) will drive further improvements in detection limits, species differentiation, and multi-element speciation. Cloud-based instrument control and predictive maintenance are poised to increase uptime and data quality in high-throughput laboratories.

Conclusion

This issue demonstrates that combining optimized ICP-MS hardware (HMI, collision mode, ISIS-DS), innovative nebulizer designs, and flexible calibration approaches delivers reliable, sensitive, and efficient analysis across environmental, clinical, and industrial matrices. Continued instrument refinement and community collaboration will support emerging analytical challenges and regulatory demands.

References

1. Sakai T., Wilbur S., Routine Analysis of Toxic Arsenic Species in Urine Using HPLC with ICP-MS, Agilent application note 5989-5505EN.
2. Todolí J.L., Mermet J.M., Liquid Sample Introduction in ICP Spectrometry: A Practical Guide, Elsevier, 2006, ISBN 978-0-444-53142-1.