Performance of the DST-1000 & DST-4000 Acid Purification Systems

Significance of the Topic

The ultra-sensitive detection capabilities of ICP-MS and other metal analysis techniques require acids of the highest purity. Commercially available high purity acids are costly and prone to contamination once opened. On-demand acid purification via sub-boiling distillation offers a cost-effective and reliable alternative for laboratories engaged in trace metal analysis, sample digestion, and standards preparation.

Study Objectives and Overview

This work evaluates the performance of Savillex DST-1000 and DST-4000 Acid Purification Systems in converting trace metal grade acids (HNO₃, HCl, HF) into ultra-pure acids suitable for ICP-MS and related applications. The study compares purity, production rate, and operational features of both systems.

Methodology and Instrumentation

• Acid Purification Principle: Sub-boiling distillation in a single PFA vessel acting as reservoir and condenser.
• Systems Compared: DST-1000 (1 L capacity, three fixed temperature settings) and DST-4000 (4 L capacity, programmable 40–95 °C controller, automatic shut-off at 500 mL).
• Analytical Instruments: Agilent 7500cs and 8800 ICP-MS for trace metal quantification; quadrupole ICP-MS and TIMS for geochemical element blanks.

Main Results and Discussion

Single-pass distillation of trace metal grade acids in both systems yielded metal concentrations consistently below 10 ppt, matching or exceeding commercial high purity (10 ppt) grades. Key findings:

• HNO₃: All measured elements (Li, Na, Mg, Al, etc.) were <1–<7 ppt, equivalent to unopened commercial acid.
• HCl: DST-produced HCl demonstrated lower levels of Ni, Ti, As and effectively removed Hg (<1 ppt), making it ideal for cold vapor AA.
• HF: Metal levels in distilled HF paralleled commercial high purity grade with most analytes <3 ppt.
• Geochemical Elements: Blanks for Rb, Sr, Nd, Sm, Th, U and others were comparable to historical compressed gas HCl/TIMS standards, confirming suitability for ultra-trace geochemistry.

Benefits and Practical Applications

• Cost Reduction: Up to ten-fold savings over bottled high purity acids.
• On-Demand Purity: Fresh acid production minimizes airborne and handling contamination.
• Operational Convenience: Compact fume hood footprint, no cooling water, simple fill-and-go operation.
• Automation: DST-4000 auto shut-off enhances safety and frees operator time.

Future Trends and Applications

Advances may include higher throughput models, remote monitoring and control, integration with laboratory information systems, and adaptation for broader reagent classes. Field-deployable units and further automation could expand use in environmental monitoring, nuclear forensics, and semiconductor manufacturing.

Conclusion

The Savillex DST-1000 and DST-4000 provide reliable, cost-effective production of ultra-pure acids on demand. Their sub-boiling distillation approach meets stringent quality requirements for trace metal and geochemical analyses while reducing contamination risks and operational expenses.

References

• Savillex Technical Note: Performance of the DST-1000 & DST-4000 Acid Purification Systems, Savillex Corporation.
• Jacobsen S., Harvard University: Comparative acid blank levels by ICP-MS and TIMS.