Agilent ICP-MS Journal (October 2012 – Issue 51)

Importance of Topic

Advances in inductively coupled plasma mass spectrometry (ICP-MS) instrumentation and methods are crucial for trace-level detection and speciation of emerging contaminants in environmental, industrial and food matrices. Improved collision/reaction cell technology and tandem quadrupole (MS/MS) configurations enhance sensitivity, selectivity and robustness when analyzing complex samples.

Goals and Overview of Studies

1. Develop and validate an IC-ICP-MS method for quantifying iodinated contrast media (iopromide) in surface and wastewater.
2. Deploy the first Agilent 8800 ICP-QQQ in the US to improve accuracy for challenging industrial matrices (e.g., flue gas desulfurization solvents).
3. Install the first European 8800 ICP-QQQ at HZG for coastal pollution monitoring and combined chemical-biological assessments.
4. Implement an LC-ICP-MS approach for arsenic speciation in apple juice to ensure compliance with drinking-water limits.

Methodology and Instrumentation

• Sample Preparation: Filtration and simple dilution (2×) for apple juice; grab-sample collection and passive/active enrichment (polymer sheets, mussel cages) for environmental waters.
• Chromatography: Anion-exchange separation using Dionex AG16 guard and AS16 analytical columns; Agilent 1200/1260 Infinity HPLC systems.
• ICP-MS Platforms: Agilent 7700x ICP-MS with helium collision cell (HMI introduction) for iopromide; Agilent 8800 triple quadrupole ICP-MS (MS/MS mode) for complex matrices; high-resolution ICP-MS and ESI/MALDI-MS for speciation support.
• Key Features: Q1 mass filtering eliminates non-target masses; ORS3 cell reaction chemistry removes polyatomic interferences; Peltier-cooled spray chamber and solid-state RF generator enhance stability.

Main Results and Discussion

• Iopromide Method: Achieved linear calibration from 0.1 to 1000 ppb; method reporting limit of 0.1 ppb (≈2 ppt in water); resolved additional unknown iodinated species via compound-independent calibration based on iodine content.
• 8800 ICP-QQQ in US Labs: Demonstrated lower detection limits and improved interference removal for As, Se, Cr, P and S in high-matrix flue gas desulfurization samples; MS/MS mode enabled precise reaction control.
• HZG Application: Equipped for spatial–temporal distribution studies of PBT substances in the North Sea; integration of chemical enrichment (passive/active samplers) with biomarker measurements (CYP450, HSP) for effect-oriented monitoring.
• Arsenic Speciation in Apple Juice: Resolved As(III), As(V), DMA, MMA and AB at low 10s ppt; total inorganic As ranged from 0.1 to 3 ppb, well below the 10 ppb threshold; simple sample prep preserved species integrity.

Benefits and Practical Applications

• Environmental Monitoring: Reliable quantification of persistent contaminants and iodine-based disinfection by-products (I-DBPs).
• Regulatory Support: Data generation for USEPA guideline updates on power plant effluent and drinking-water safety.
• Food Safety: High-throughput arsenic speciation in beverages to protect public health.
• Industrial R&D: Trace element mapping in carbon capture solvents and advanced materials.

Future Trends and Opportunities

• Broader adoption of MS/MS ICP-QQQ for multi-element speciation and ultra-trace analyses in regulated sectors.
• Integration of passive environmental samplers with triple quadrupole ICP-MS for combined chemical and biological effect assessment.
• Expansion of compound-independent calibration approaches for emerging pollutants.
• Continued development of novel reaction gases and cell chemistries to tackle new interference challenges.

Conclusion

Recent developments in ICP-MS, especially tandem quadrupole configurations and advanced collision/reaction cell technologies, deliver unmatched sensitivity and interference control. Validated methods for iopromide in waters and arsenic speciation in apple juice, alongside rapid adoption of the Agilent 8800 ICP-QQQ system, demonstrate the technique’s transformative impact on environmental, industrial and food-safety analyses.

Instrumental Section

• Agilent 7700x ICP-MS with HMI sample introduction and He collision mode.
• Agilent 8800 triple quadrupole ICP-MS (MS/MS mode).
• Agilent 1200 and 1260 Infinity HPLC systems.
• Dionex AG16 guard (4 × 50 mm) and AS16 analytical (4 × 250 mm) anion-exchange columns.
• Peltier-cooled spray chamber and fast solid-state RF generator.

References

1. Agilent Application Note: Determination of iopromide in environmental waters by ion chromatography-ICP-MS, 5991-1044EN.
2. Agilent Application Note: Arsenic speciation analysis in apple juice using HPLC-ICP-MS, 5991-0622EN.