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

Importance of the topic

Environmental and industrial matrices often present unknown compositions, high dissolved solids and demanding throughput requirements. Advances in ICP-MS sample introduction, collision/reaction cell technologies and fully heated interfaces are critical to deliver fast, accurate, interference-free trace element and organometallic analyses across environmental, biological and petrochemical applications.

Objectives and study overview

This Issue #42 (May 2010) of the Agilent ICP-MS Journal highlights four major developments:

• Simplified EPA Method 6020A compliance using Agilent 7700x ICP-MS with High Matrix Introduction (HMI) and helium collision mode.
• Rapid HPLC-ICP-MS screening of polybrominated diphenyl ether (PBDE) congeners and metabolites in rat liver and feces employing a fast frequency-matching RF generator.
• Introduction of a fully heated, inert GC-ICP-MS interface kit to extend the volatile and high-boiling compound analysis capability of Agilent 7890A GC coupled to 7700 Series ICP-MS.
• Preview of high-temperature simulated distillation (SimDis) by GC-ICP-MS for simultaneous carbon and sulfur profiling in petroleum fractions.

Methodology and instrumentation

• EPA 6020A: Agilent 7700x ICP-MS was operated with robust plasma tuning (CeO+/Ce+<1%), HMI mid-level dilution (carrier gas 0.6 L/min, dilution gas 0.4 L/min), helium collision gas for polyatomic interference removal and no-gas mode for unaffected analytes.
• PBDE HPLC-ICP-MS: Agilent 7700x with frequency-matching RF generator and ORS octopole cell was coupled to an Agilent 1200 LC using a 4.6×50 mm, 1.8 µm C18 column at 1.5 mL/min with a 70–95% acetonitrile gradient. Helium (2 mL/min) and argon carrier (0.65 L/min), 8% O₂ addition, and spray chamber at –5 °C ensured stable plasma under high organic load.
• GC-ICP-MS interface: The G3158C kit features a Sulfinert® stainless steel-lined transfer line and injector fully heated up to 300 °C, self-centering torch injector, docking station and independent temperature control of GC transfer line and ICP injector.
• High-temperature SimDis: Utilizes the same fully heated interface and dry plasma to deliver <100 ms residence time from GC to ICP, enabling introduction and detection of hydrocarbons up to C₉₀ and simultaneous 13C/32S monitoring.

Key results and discussion

• EPA 6020A: Method Detection Limits (MDLs) for 24 elements ranged from 0.004 to 3.17 µg/L under real-sample conditions; 156-sample, 15-hour sequence met all QA/QC criteria with no internal standard recoveries falling below the 70% limit. Recoveries for certified reference materials ranged 91–112% across waters, soils and sediments.
• PBDE screening: Baseline separation achieved for congeners BDE-47 to BDE-206; 207/208 coelute. He collision mode allowed direct infusion of 95% acetonitrile at 1.5 mL/min. Detection limits ~20 ng/mL (as Br). In rat studies, no metabolites were detected; BDE-209 concentrations in liver (7.9 ± 0.2 mg/L) and feces (14.1 ± 1.1 mg/L) were quantified by standard addition with RSD ~7%.
• GC-ICP-MS interface: Analysis of a mixed organotin standard in <12 min achieved a TBT detection limit of 5.9 ppt. Dry plasma operation eliminated background interferences on sulfur and phosphorus, enabling trace organotin speciation.
• SimDis by GC-ICP-MS: Carbon marker compounds from C₄₀ to C₉₀ were resolved, and simultaneous carbon (13C) and sulfur (32S) profiles were obtained for a sulfur-in-diesel standard (NIST 2724B), illustrating boiling point distributions alongside sulfur content.

Benefits and practical applications

• Single-mode helium collision cell simplifies EPA 6020A compliance across unknown, high-matrix environmental samples without prior matrix knowledge or complex tuning.
• HPLC-ICP-MS workflow supports rapid, interference-free speciation of halogenated organic pollutants in biological matrices without radioactive detectors.
• Fully heated GC interface removes condensation and inertness issues, expanding routine GC-ICP-MS to organotins, fuel quality control and high-boiling compounds.
• SimDis by GC-ICP-MS offers simultaneous elemental (C, S) and boiling point profiling, aiding petroleum feedstock evaluation and sulfur regulation compliance.

Future trends and opportunities

• Broader adoption of helium collision–based speciation for metalloids and nanoparticle analysis under complex matrix conditions.
• Enhanced tolerance to organic solvents through frequency-matched RF generators, supporting faster UHPLC gradients and higher organic content.
• Development of multi-element boiling point distillation profiles (C, S, Ni, V) for comprehensive petrochemical characterization.
• Integration of automation and AI-driven data analysis for high-throughput QA/QC in environmental, food and pharmaceutical laboratories.

Conclusion

Agilent’s innovations—including High Matrix Introduction, helium collision mode, frequency-matching RF generators and a fully heated GC-ICP-MS interface—significantly enhance ICP-MS versatility and robustness. These advances streamline complex sample analyses, deliver reliable trace element and organometallic determinations, and open new applications in environmental monitoring, toxicology, fuel characterization and regulatory compliance.

Instrumention

• Agilent 7700x ICP-MS with High Matrix Introduction, ORS helium collision cell and frequency-matching RF generator.
• Agilent 7500ce ICP-MS and 1200 LC system for PBDE separations.
• Agilent 7890A GC coupled to 7700 Series ICP-MS via the G3158C fully heated Sulfinert® interface.

Reference

1. “Decabromodiphenyl ether,” Wikipedia; K. Bierla et al., J. Anal. At. Spectrom. 2010, DOI: 10.1039/C000686F.