Agilent ICP-MS Journal (August 2006 – Issue 28)

Significance of the Topic

ICP-MS has evolved into a versatile platform not only for routine trace-element assays in liquid matrices but also for direct analysis of gaseous and complex samples. Its high sensitivity, coupled with collision/reaction cell technology and automated sample introduction, opens new possibilities in environmental monitoring, industrial quality control, and clinical speciation studies.

Objectives and Overview

This issue presents a series of developments and success stories around Agilent’s 7500 Series ICP-MS instruments and associated accessories. Key topics include:

• Direct real-time analysis of particulate matter in gas samples via a novel gas-exchanger interface.
• Certification of an ICP-MS-based multi-element water analysis method at Nestlé Waters’ global quality center.
• Introduction of ChemStation software revision B.03.03 with enhanced tuning, data-acquisition and batch-review features.
• Routine speciation of five arsenic compounds in human urine employing an optimized HPLC-ICP-MS procedure.
• New all-PFA inert sample introduction kit and concentric nebulizer for enhanced long-term stability with challenging matrices.
• Discussion of collision cell compliance for EPA Method 200.8 in drinking water analysis.

Methodology and Instrumentation

Several novel or enhanced components and workflows are described:

• Gas-Exchanger System
  • Counter-current argon sweep through a porous tube to capture sub-micron particulates from sample gases (flow up to 500 mL/min).
  • Aspirator and pressure equalizer maintain constant gas delivery into the plasma.
  • Agilent 7500cs ICP-MS for high-sensitivity detection of metal particulates (0.01–0.1 µm).
• Water Analysis at Nestlé Waters
  • Agilent 7500ce ICP-MS equipped with Octopole Reaction System (ORS) to remove interferences.
  • ISIS autosampler and CETAC ASX-520 for high throughput.
  • Validation under COFRAC accreditation against ISO 17294-2:200 (62-element suite, <1 µg/L detection).
• ChemStation Rev. B.03.03 Software
  • Multimode autotune (no-gas, He, H₂) in one click; system-wide tuning parameters.
  • Pre-run monitor for up to six masses; offline method editing during runs.
  • Batch View table display of concentration and CPS in real time; graph summary of calibration curves.
• Arsenic Speciation in Urine
  • Agilent 1100 Series HPLC (isocratic, vacuum degasser, thermostatted compartment) coupled to 7500ce ICP-MS.
  • Agilent G3288-80000 anion-exchange column and G3154-65002 guard column; phosphate/EDTA/acetonate mobile phase at pH 11.
  • MicroMist glass concentric nebulizer; direct 5 µL injection of undiluted urine yields <0.1 µg/L LOD for As species.
• Inert Sample Introduction Kit and Nebulizer
  • All-PFA kit (G3285A) with o-ring-free torch connector, push-fit design and optional second gas port for O₂ addition.
  • PFA concentric nebulizer (200 µL/min) compatible with inert kit and integrated autosampler probes.
• Collision Cell Compliance for EPA Method 200.8
  • Discussion of quality-assurance criteria needed to validate CRC-ICP-MS for regulatory drinking water analysis.
  • Support for performance-based interference check standards in lieu of mathematical correction equations.

Main Results and Discussion

The gas-exchanger system maintained full sensitivity for Mo and W reference gases even with up to 500 mL/min of N₂, CO₂ or 10% SO₂ sample flows. Ambient air analysis revealed real-time iron spikes from suspended particulates. At Nestlé Waters, the 7500ce ORS ICP-MS replaced dual OES/AAS workflows, improving detection limits, throughput and operational flexibility under COFRAC accreditation for 56 elements. The ChemStation B.03.03 upgrade reduced manual tuning time, enabled simultaneous multimode autotuning, and provided real-time batch monitoring. In clinical speciation, the new column chemistry fully resolved As(III), As(V), DMA, MMA and arsenobetaine within 12 minutes, eliminating chloride-based ArCl interference. The all-PFA kit and nebulizer deliver droplet-free operation and long-term stability for challenging solvents and high dissolved solids matrices.

Benefits and Practical Applications

• Direct gas-phase ICP-MS analysis for ambient air monitoring, exhaust gas surveillance and rapid screening of particulate-bound metals.
• Single-instrument, multi-element water testing with trace-level detection for global beverage quality control and regulatory compliance.
• Streamlined IQ/OQ and routine operations via advanced software features, reducing downtime and operator workload.
• Fast, sensitive arsenic speciation in clinical and environmental urine samples without dilution or complex sample prep.
• Robust, inert sample introduction options for organic solvents, high-matrix samples and long sequence stability.
• Roadmap toward EPA acceptance of collision cell-enabled ICP-MS for drinking water under Method 200.8.

Future Trends and Opportunities

Ongoing research aims to standardize calibration protocols for metal gas standards and to extend real-time gas monitoring to automotive exhaust and industrial emissions. In beverage and process water, the focus will shift to ultra-trace analytes—such as bromine in added salts and iodine in processing aids—and mercury speciation at sub-ppb levels. Regulatory bodies and accreditation programs are anticipated to finalize CRC-ICP-MS quality-assurance guidelines, broadening approved applications across matrices.

Conclusion

The integration of innovative sample-introduction hardware, advanced collision/reaction cell technology, and user-friendly software substantially enhances the versatility and performance of Agilent’s 7500 Series ICP-MS platforms. These developments support high-sensitivity, high-throughput analyses across gas, liquid and complex matrices, meeting the evolving demands of environmental monitoring, industrial QA/QC, and clinical speciation.