Extraction of formic and acetic acids from aqueous solution by dynamic headspace-needle trap extraction temperature...

Area of Science:

• Analytical Chemistry
• Environmental Chemistry

Background:

• Short-chain fatty acids like formic and acetic acids are important environmental analytes.
• Accurate determination of these acids in aqueous solutions presents analytical challenges.

Purpose of the Study:

• To develop and validate a combined dynamic headspace-needle trap extraction (HS-NTE) method for determining formic and acetic acids.
• To optimize key parameters for the HS-NTE technique.

Main Methods:

• A needle extraction device coupled with a gas aspirating pump was used for sampling and preconcentration.
• The needle trap extraction (NTE) technique was employed under dynamic conditions with a constant headspace volume.
• Extraction temperature and acidification effects were optimized.

Main Results:

• The developed method achieved detection limits of 87.2 µg/L for acetic acid and 234.8 µg/L for formic acid.
• Despite challenges with formic acid detection, the method demonstrated good precision (4.7-10.7%) in real samples.
• The HS-NTE method was successfully applied to analyze environmental samples.

Conclusions:

• The combined dynamic headspace-needle trap extraction and gas chromatography method is effective for determining short-chain fatty acids in aqueous solutions.
• This validated method provides a sensitive and precise approach for analyzing formic and acetic acids in environmental matrices.