Routine soil analysis using an Agilent 8800 ICP-QQQ

Significance of the topic

Accurate, high-throughput, multi-element soil analysis is critical for environmental monitoring, regulatory compliance and quality control in agriculture, mining and waste management. Conventional quadrupole ICP-MS delivers high sensitivity but can suffer spectral interferences from complex matrices and doubly-charged rare earth elements, especially for arsenic and selenium at trace levels. The development of a triple quadrupole ICP-MS with advanced matrix tolerance and interference removal addresses these challenges and streamlines routine soil and sediment testing.

Objectives and study overview

This study evaluates the performance of the Agilent 8800 Triple Quadrupole ICP-MS equipped with High Matrix Introduction (HMI) technology for the routine analysis of 28 elements, including arsenic and selenium, in soil and sediment digests. Key aims include testing interference removal in MS/MS modes, assessing method detection limits, verifying stability and accuracy over extended runs, and demonstrating compliance with EPA Method 6020A quality control requirements.

Methodology and instrumentation

Sample digestion followed standard soil and sediment protocols. Certified reference materials (five CRMs of river and estuarine sediments and soils) and matrix-matched calibration standards were prepared in mixed nitric and hydrochloric acid. A multi-tune acquisition method measured most elements in helium collision mode and As/Se in oxygen mass-shift mode using MS/MS. The preset HMI-4 plasma conditions ensured consistent aerosol dilution for samples up to percent-level total dissolved solids. Online internal standard addition and auto-tuning maintained signal stability over a 12-hour, 177-analysis sequence with ~4 min per sample throughput.

Instrumentation

Agilent 8800 ICP-QQQ
Quartz spray chamber and concentric nebulizer
Octopole collision/reaction cell with He and O₂ gases
Online internal standard addition kit
High matrix introduction (HMI) technology
Ni interface cones

Main results and discussion

Method detection limits (MDLs) were in the low ppt range for most trace elements and sub-ppb for As/Se, with practical quantitation limits three times the MDLs. Internal standard recoveries remained within 30–120 % over 130 samples, meeting EPA criteria. Continuing calibration verification recoveries stayed within ±10 % over 12 hours. Oxygen mass-shift MS/MS effectively eliminated doubly-charged REE interferences for As and Se, yielding results consistent with certified values even without HF digestion. Analysis of five CRMs in replicate (n=26 each) showed mean recoveries within 90–110 % and RSDs below 5 % for nearly all elements.

Benefits and practical applications

The Agilent 8800 ICP-QQQ offers robust high-matrix tolerance comparable to single quadrupole systems while adding tandem MS capabilities for reliable interference removal. Simplified method setup with preset plasma conditions and auto-tuning reduces operator dependency. The workflow enables routine environmental and food safety labs to quantify critical elements like As and Se accurately in complex soil and sediment matrices, ensuring regulatory compliance and confidence in data.

Future trends and potential applications

Wider adoption of triple quadrupole ICP-MS is expected in geoscience, agriculture, food safety and life-science applications. Further improvements in reaction cell chemistries, automated method optimization and coupling with laser ablation or field-deployable sampling could expand capabilities. Integration with advanced data analytics and real-time monitoring will enhance throughput and decision-making in environmental assessment and industrial QA/QC.

Conclusion

The Agilent 8800 ICP-QQQ with HMI technology delivers exceptional sensitivity, stability and interference control for multi-element soil and sediment analysis. MS/MS mass-shift modes effectively remove challenging polyatomic and doubly-charged interferences, notably for arsenic and selenium. The method meets stringent quality control criteria and provides accurate, reproducible results in demanding high-matrix samples, supporting routine environmental and industrial testing needs.

References

1. Ed McCurdy and Glenn Woods, Journal of Analytical Atomic Spectrometry, 2004, 19, 607–615
2. Agilent 8800 ICP-QQQ Application Handbook, 2nd Edition, 2015, Publication 5991-2802EN
3. Silvia D. Fernandez et al., Analytical Chemistry, 2012, 84, 5851–5857
4. Takeshi Ohno and Yasuyuki Muramatsu, Journal of Analytical Atomic Spectrometry, 2014, 29, 347–351
5. Glenn Woods, Agilent Application Note, 2014, 5991-5270EN
6. Brian P. Jackson et al., Journal of Analytical Atomic Spectrometry, 2015, 30, 1179–1183
7. Steve Wilbur and Craig Jones, Agilent Application Note, 2010, 5990-5514EN
8. Kazuo Yamanaka and Steve Wilbur, Agilent Application Note, 2014, 5991-5208EN