Unlocking the secrets of the Antartic with the aid of ultrapure water

Importance of the Topic

Antarctica remains one of the most unspoiled environments on the planet. Ultra-trace chemical analysis of ice cores, snow, aerosols and seawater yields unique insights into past and present climate conditions, atmospheric composition and environmental changes. Achieving reliable results at sub-picogram levels demands meticulous contamination control and the use of ultrapure water throughout sample cleaning and preparation.

Study Objectives and Overview

This case study describes the contribution of the Italian National Antarctic Research Programme (PNRA) and CNR-IDPA/Università Ca’ Foscari Venice to long-term monitoring of trace chemicals in Antarctic matrices. The expedition aimed to collect air, water and snow samples, isolate persistent organic pollutants (POPs), rare earth elements (REEs) and other ultratrace species, and track temporal variations in background concentrations down to sub-picogram per gram levels.

Methodology and Instrumentation

The 27th PNRA expedition (2011–2012) deployed the research vessel Italica, equipped with a containerized clean room (Class 1000) and dedicated on-board laboratory. Sampling bottles constructed from polyethylene and Teflon underwent a rigorous multi-week cleaning protocol at the Venice laboratory. Cleaning steps included:

• Repeated rinsing with Type I ultrapure water from an ELGA PURELAB Ultra coupled with Option-Q.
• Acidification with 0.1 % high-purity HCl prepared using the same ultrapure water.
• Triple-bagging and heat sealing before shipment to Antarctica.

Onboard, a PURELAB flex 3 unit maintained a continuous supply of ultrapure water for equipment decontamination and blank preparation. Samples returned to Venice were analyzed using:

• Inductively coupled plasma sector field mass spectrometry (ICP-SFMS) with microflow nebulization/desolvation for trace metals and rare earth elements.
• HPLC-ESI-MS/MS for organic tracers such as levoglucosan.
• Dedicated aerosol and air sampling instrumentation for POPs and mercury determinations.

Main Results and Discussion

Over 300 frozen samples were collected and processed without detectable procedural contamination. Ultrapure water systems delivered stable resistivity (>18.2 MΩ·cm) under harsh maritime conditions. Analytical methods achieved detection limits in the sub-picogram per gram range, enabling precise mapping of background levels and identification of temporal trends in aerosol composition, trace metals and organic markers.

Benefits and Practical Applications of the Method

The described approach ensures:

• Uncompromised sample integrity through rigorous cleaning and ultrapure water use.
• High-sensitivity detection of ultratrace analytes in environmental matrices.
• Reproducible, contamination-free workflows suitable for remote field campaigns.

Future Trends and Opportunities

Advances may include miniaturized, automated onboard purification systems; real-time coupling of ultrapure water generation with portable analytical instruments; and expanded monitoring of emerging contaminants. Integration of digital performance monitoring and remote diagnostics will further enhance reliability during polar expeditions.

Conclusion

This case study highlights the critical role of ultrapure water in ultra-trace environmental analysis. ELGA LabWater systems provided the necessary contamination control to support high-precision measurements of Antarctic samples, underpinning studies on climate history and ongoing environmental change.

References

• Toretta C., Cozzi G., Barbante C., Capodaglio G., Cescon P. "Trace element determination in seawater by ICP-SFMS coupled with a microflow nebulisation/desolvation system." Anal. Bioanal. Chem., 2004, 380: 258–268.
• Planchon F.A.M. et al. "Direct determination of mercury at the sub-picogram per gram level in polar snow and ice by ICP-SFMS." J. Anal. At. Spectrom., 2004, 19: 823–830.
• Gambaro A., Zangrando R., Gabrielli P., Barbante C., Cescon P. "Direct determination of levoglucosan at the picogram per millilitre level in Antarctic ice by HPLC/ESI-MS/MS." Anal. Chem., 2008, 80(5): 1649–1655.
• Gabrielli P. et al. "Direct determination of rare earth elements at the subpicogram per gram level in Antarctic ice by ICP-SFMS using a desolvation system." Anal. Chem., 2006, 78: 1883–1889.