Agilent ICP-MS Journal (May 2010 – Issue 42)

Importance of the Topic

Inductively coupled plasma mass spectrometry (ICP-MS) is an essential tool in environmental and industrial analysis due to its high sensitivity and multi-element capability. Recent advances aim to expand its versatility for high matrix samples, complex speciation, and high-boiling compounds, addressing challenges in reliability, throughput and interference elimination.

Objectives and Study Overview

This issue presents four case studies illustrating innovations in ICP-MS instrumentation and methodology: EPA 6020A compliance using Agilent 7700x with High Matrix Introduction (HMI) and helium collision mode; HPLC-ICP-MS screening of polybrominated diphenyl ether metabolites in biological samples; a new fully heated GC-ICP-MS interface kit for analysis of volatile and organometallic species; and high-temperature simulated distillation by GC-ICP-MS for ultra-heavy hydrocarbon and sulfur speciation.

Methodology and Instrumentation

• Agilent 7700x ICP-MS with patented HMI system and helium collision cell (no gas mode for high matrix tolerance) for EPA 6020A trace metal analysis of certified waters, soils and sediments.
• HPLC-ICP-MS coupling with frequency-matching RF generator and octopole collision cell on 7700x for rapid screening of PBDE congeners, using reversed-phase UHPLC with acetonitrile gradients, optimized for bromine monitoring.
• Fully heated, inert Sulfinert®-lined GC-ICP-MS interface kit (G3158C) connecting 7890A GC to 7700 Series ICP-MS, with stable plasma conditions at elevated temperatures for organotin speciation.
• Uniformly heated transfer line and injector to 300 °C and dry plasma operation enabling high-temperature (>600 °C) SimDis analysis of hydrocarbons up to C90 and sulfur reference standards, with 12 ms transport time to plasma and interference-free sulfur detection.

Main Results and Discussion

• EPA 6020A: Seven-replicate MDLs in the ppb range for 28 elements; internal standard recoveries above 70 % over 15 hour, 156-sample runs; accurate CRM recoveries (91–108 %).
• PBDE HPLC-ICP-MS: Baseline separation of nine PBDE congeners (47–209) at 1.5 mL/min with up to 95 % acetonitrile; LOD ~20 ng/mL Br; quantification of BDE-209 in rat liver (7.9 ± 0.2 mg/mL) and feces (14.1 ± 1.1 mg/mL).
• GC-ICP-MS Interface: Sub-ppt detection of organotins in <12 min runs; TBT detection limit 5.9 ppt; robust long-term operation without condensation or tailing; demonstrated for fuel sulfur speciation and PBDE separation.
• High-Temperature SimDis: Discrete peaks detected C40–C90 hydrocarbons; simultaneous C and S monitoring with extracted ions 13C and 32S; reliable speciation of heavy fractions and sulfur distribution in petroleum samples.

Benefits and Practical Applications

This collection of methods offers:

• Simplified workflows for high-matrix environmental and industrial samples with minimal sample prep and consistent detection limits.
• Enhanced speciation capabilities for organic pollutant metabolites, flame retardants, organotins and sulfur species in complex matrices.
• High-throughput analysis with extended continuous operation, reducing downtime and calibration frequency.
• Versatile coupling of ICP-MS with HPLC and GC for a broad boiling range (volatile organics to heavy hydrocarbons).

Future Trends and Potential Applications

Ongoing developments are expected to focus on:

• Integration of advanced cell gases and reaction chemistries for selective interference removal.
• Automated, real-time coupling of separation techniques with ICP-MS for online monitoring in environmental and industrial processes.
• Further miniaturization and field-deployable ICP-MS systems for on-site high matrix and speciation analysis.
• Advanced data processing and machine learning for enhanced interpretation of multi-dimensional ICP-MS datasets.

Conclusion

The highlighted innovations demonstrate the expanding capabilities of ICP-MS to handle challenging matrices, complex speciation tasks, and high-boiling analytes through optimized interfaces, collision modes and high-temperature transfer systems. Together, these methods increase reliability, throughput and analytical depth across environmental, pharmaceutical and petrochemical applications.

References

1. Agilent Technologies Application Note 5990-5514EN, “Simple, Reliable EPA 6020A Analysis Using the Agilent 7700x ICP-MS.”
2. Bierla K, Szpunar J, Bouyssiere B. Journal of Analytical Atomic Spectrometry 2010, DOI:10.1039/C000686F.
3. Agilent Technologies GC-ICP-MS Interface Kit G3158C Documentation.
4. Wilbur S. “High Temperature Simulated Distillation by GC-ICP-MS,” Agilent ICP-MS Journal, Issue 42, May 2010.