High sensitivity tin speciation using a new GC interface with Sector Field High Resolution ICP-MS

Significance of the Topic

Accurate tin speciation is critical because different organotin compounds exhibit widely varying toxicity and environmental behavior. While total tin concentration offers limited insight, distinguishing between species such as tributyltin (TBT) and less toxic forms is essential for regulatory compliance and risk assessment.

Objectives and Study Overview

This study evaluates the performance of a novel Gas Chromatography–Inductively Coupled Plasma Sector Field Mass Spectrometry (GC–SF ICP-MS) interface (GCI 200) for high-sensitivity tin speciation. The work focuses on system integration, chromatographic separation of 14 organotin species, detection limits, and method robustness.

Methodology and Instrumentation

A Thermo Scientific TRACE 1310 GC, equipped with an auxiliary temperature module, was coupled via the GCI 200 interface to a Thermo Scientific ELEMENT XR high-resolution SF ICP-MS.

• GC conditions: 1 µL splitless injection, TG-1MS column (30 m × 0.25 mm × 0.25 µm), helium carrier gas (initial 5 mL/min, ramped to 2.6 mL/min), controlled temperature program to avoid cold spots.
• ICP-MS settings: plasma power 1150 W, sample gas 1.12 L/min Ar, monitoring 118Sn, 120Sn and 132Xe isotopes, low resolution (m/Δm = 300), 89 ms scan cycle.
• Interface conditions: transfer line at 305 °C, flexible design minimizes dead volume and thermal gradients.

Main Results and Discussion

The integrated system achieved baseline separation of 14 organotin species, including MBT, DBT, MPhT, TBT, MOT, TTBT, DPhT, DOT, TPhT, TCyT, TPT, TTPT, MHT and DHT, at 6.1 ppb levels. Sector Field ICP-MS delivered exceptional signal intensities (on the order of 1e7 cps for 6.1 ppb MBT/DBT/TBT) and low background noise, yielding sub-ppt detection limits. Chromatograms showed sharp peaks without broadening, thanks to the stable temperature profile and absence of condensation in the transfer line. Memory effect studies with 14 successive high-standard/blank cycles revealed negligible carryover and consistent baseline performance.

Benefits and Practical Applications

• High sensitivity and low detection limits enable trace-level monitoring of toxic organotins in environmental and food matrices.
• Robust chromatographic performance reduces peak tailing and broadening for compounds with diverse boiling points.
• Minimal memory effects and fast interface installation support high sample throughput in QA/QC and research laboratories.

Future Trends and Opportunities

Advances in GC–ICP-MS interfaces will likely focus on further miniaturization, enhanced thermal control and integration with automated sample preparation. Combining high-resolution mass spectrometry with speciation workflows opens opportunities for broader multi-element speciation studies and real-time monitoring of emerging contaminants.

Conclusion

The GCI 200 interface coupled with the ELEMENT XR SF ICP-MS delivers a powerful platform for high-sensitivity, reliable tin speciation. Its ease of installation, stable thermal performance and minimal carryover make it well suited for demanding analytical tasks in environmental, food and industrial applications.

References

No formal literature list was provided in the source text.