Coupling of ion chromatography and inductively-coupled plasma mass spectrometry

Importance of the topic

Ion chromatography hyphenated to inductively coupled plasma mass spectrometry (IC-ICP-MS) combines molecular and elemental selectivity, enabling precise speciation at trace levels across environmental, pharmaceutical, water quality, and food and beverage analysis.
This technique is essential for assessing toxicity, bioavailability, and compliance with low-level regulatory standards.

Objectives and overview

• Describe online hyphenation of IC and ICP-MS with automated sample preparation
• Outline modular IC and ICP-MS instrumentation for flexibility and reliability
• Review key applications for elemental speciation in diverse matrices

Instrumentation

• 940 Professional IC Vario: modular design, inline eluent preparation, multi-detection, gradient operation
• ICP-MS: high-sensitivity quadrupole systems with collision cell, remote synchronization, detection limits in pg/L

Methodology

• Automated coupling: sample injection, gradient separation, suppressor modes, remote control for data synchronization
• Speciated Isotope Dilution Mass Spectrometry (SIDMS, EPA 6800) to correct interspecies transformations
• Customized column chemistries and eluent compositions per target analyte

Main results and discussion

• Chromium: baseline separation of Cr(III)/Cr(VI), detection limits in ng/L, validated against NIST SRMs in soils, consumer goods, supplements
• Arsenic: simultaneous speciation of As(III), As(V), MMA, DMA, AsB, TMAO in supplements, refineries, fish tissues with gradient IC-ICP-MS
• Mercury: speciation of Hg(II) and MeHg+ in fish, crude oil, hair samples; SIDMS corrects extraction artifacts; detection sub-μg/L
• Iodine: monitoring iodinated X-ray contrast media degradation to iodate during ozonation by IC-ICP-MS
• Gadolinium: transmetallation assessment of gadolinium chelates under Fe3+ flocculation in wastewater; macrocyclic versus linear stability
• Selenium: separation of Se(IV), Se(VI), and SeCN−; combined As/Se speciation in refinery waters
• Thallium: detection of organic Me2Tl+ and inorganic Tl+ in environmental waters; retention on cation-exchange with ICP-MS detection
• Iron: Fe(II)/Fe(III) speciation by DPA complexation in soils and beverages; fast separation in <5 min
• Organic compounds: indirect detection of aminopolycarboxylates (EDTA, CDTA, DTPA) via metal complexation
• Antimony: Sb(III)/Sb(V) speciation and nanoparticle analysis in urban PM and brake dust
• Bromate: microbore IC-ICP-MS for sub-μg/L bromate in drinking water without sample pretreatment

Benefits and practical application

• Fully automated workflows reduce operator error and increase throughput
• Wide dynamic range and ultralow detection limits for trace and ultra-trace analyses
• Comply with DIN EN, EPA, ASTM, ISO standards for environmental and food safety
• Enables informed decisions in environmental monitoring, quality control, and regulatory compliance

Future trends and potential uses

• Integration with complementary detectors (UV/VIS, amperometry) for multiplexed speciation
• Microfluidic and miniaturized columns for higher throughput and reduced solvent consumption
• Targeting emerging contaminants: nanoparticles, pharmaceuticals, isotopic well tracing
• Advanced software for real-time monitoring and LIMS integration

Conclusion

IC-ICP-MS with automated IC Vario systems and SIDMS offers a versatile, robust platform for reliable speciation across diverse analytes and matrices. It meets stringent regulatory needs, ensures trace-level accuracy, and supports high-throughput laboratory operations.

References

1. Herrmann T. (2006) Ion chromatography coupled to ICP-MS. Philipps-Universität Marburg
2. Knöll J.; Seubert A. (2012) Aminopolycarboxylate detection by IC-ICP-MS. J Chrom A, 1270, 219–224
3. Rahman G.M.M. et al. (2012) EPA Method 6800 speciation of chromium. Agilent Handbook
4. Pfundstein P. et al. (2015) Iodine species in ozonation. The Column, 11(16), 9–14
5. Künnemeyer J. et al. (2009) Gadovist vs Magnevist stability. Anal Chem, 81(9), 3600–3607
6. Reyes L.H. et al. (2009) Mercury speciation in fish. J Anal At Spectrom, 24, 83–92
7. Canepari S. et al. (2010) Antimony speciation in PM. Anal Bioanal Chem, 397(6), 2533–2542
8. Nowak M.; Seubert A. (1998) Bromate in drinking water. Anal Chim Acta, 359, 193–204