Comparing and contrasting In-Vial and full-scale systems for sparging volatile analytes

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Traditional sparging systems for volatile analyte analysis can be resource-intensive.
• Developing efficient and practical alternatives is crucial for routine analysis.

Purpose of the Study:

• To evaluate in-vial sparging as a viable alternative to full-scale sparging systems.
• To develop and validate a predictive model for sparging performance.

Main Methods:

• In-vial sparging experiments were conducted using elemental mercury (Hg0) and toluene as model analytes.
• Mass removal was quantified using atomic absorption/fluorescence spectroscopy (for Hg0) and UV-Vis spectroscopy (for toluene).
• A reduced-order model incorporating dimensionless Henry's Law coefficient and normalized sparge gas volume was developed and validated.

Main Results:

• The in-vial sparge system demonstrated effective mass removal for both Hg0 and toluene.
• The developed reduced-order model accurately predicted sparging performance for both analytes.
• In-vial sparging reached approximately 33% of equilibrium, while full-scale systems reached 100% under tested conditions.

Conclusions:

• In-vial sparging is a practical and effective method for analyzing volatile compounds, offering advantages in automation, waste reduction, and cost-effectiveness.
• The validated reduced-order model provides a valuable tool for optimizing in-vial sparging applications.
• In-vial sparge platforms are suitable for the analysis of volatile organic compounds and volatile metals/organometallics.