Flexible Sample Introduction with the Multimode Sample Introduction System

Importance of the Topic

The ability to switch rapidly between hydride generation and conventional nebulization in atomic spectroscopy enhances laboratory efficiency and data throughput. Agilent’s Multimode Sample Introduction System (MSIS) addresses the need for a versatile accessory that minimizes downtime, maintains consistent plasma conditions, and supports simultaneous analysis of hydride-forming and non-hydride elements.

Objectives and Study Overview

This white paper evaluates the performance of the MSIS coupled to Agilent ICP-OES and MP-AES platforms. The goals are to demonstrate the ease of switching between sample introduction modes, quantify detection limits for key analytes, and assess calibration linearity and practical benefits in routine elemental analysis.

Methodology and Instrumentation

Agilent’s Multimode Sample Introduction System was installed on an SVDV ICP-OES and an MP-AES instrument. Three sample introduction modes were tested:

• Conventional nebulization: hydride lines blocked, sample aerosol introduced into the plasma.
• Vapor generation: reductant and sample lines fed into a spray chamber to generate volatile hydrides carried by argon.
• Dual mode: both aerosol and gaseous hydride streams combined for simultaneous multi-element analysis.

Key variables included acid matrices (HCl concentrations with or without L-cysteine) and gas flows.

Main Results and Discussion

Detection limits for hydride elements (As, Hg, Sb, Se, Sn) in single-element and multi-element modes ranged from 0.037 to 2.5 µg/L depending on chemistry. Optimal acid conditions yielded the lowest limits, while a compromise matrix (4% HCl + 1% L-cysteine) delivered comparable performance in dual mode. Non-hydride elements (Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, P, Pb, Zn) achieved detection limits of 0.056 to 4.6 µg/L in dual mode, matching or improving on conventional nebulization. All hydride calibration curves were linear to 1000 µg/L, surpassing typical analytical ranges.

Benefits and Practical Applications

• Eliminates physical exchange of introduction hardware and plasma relighting.
• Enables rapid alternation or concurrent measurement of diverse element classes.
• Maintains high sensitivity and broad dynamic range for hydride and non-hydride elements.
• Reduces total analysis time and increases laboratory productivity.

Future Trends and Potential Applications

Advances may include automated control of introduction modes, integration with high-throughput sample handling, and expansion to additional vapor generation chemistries. The MSIS concept could be extended to coupling with mass spectrometry or field-deployable plasma systems for environmental and on-site monitoring.

Conclusion

The Agilent MSIS offers a flexible, time-saving solution for comprehensive elemental analysis by ICP-OES and MP-AES. It delivers excellent detection limits, linearity, and operational simplicity, making it well suited for laboratories that require both hydride and conventional measurements without downtime.

References

1. Agilent Technologies. Simultaneous analysis of hydride and non-hydride-forming elements via ICP-OES. Publication 5991-6445EN, 2019.