Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Accurate on-site gas analysis is crucial for quality control, especially for perishable goods like fruits.
• Traditional methods often lack portability or real-time capabilities for trace gas detection.
• Developing rapid, sensitive, and representative sampling techniques is essential for field applications.

Purpose of the Study:

• To develop a portable large-volume constant-concentration (LVCC) sampling technique integrated with surface-enhanced Raman spectroscopy (SERS).
• To enable rapid, on-site quantification of trace gases, specifically ethylene and sulfur dioxide (SO2), from real-world samples like fruits.
• To establish a reliable method for representative gas sampling and subsequent sensitive spectroscopic analysis.

Main Methods:

• Development of a novel LVCC sampling cell and absorption-derivatization module.
• Integration of bromine-thiourea and OPA-NH4+ derivatization strategies for efficient gas capture and SERS compatibility.
• Application of the developed LVCC-SERS method for analyzing trace ethylene and SO2 in fruit samples.

Main Results:

• The LVCC sampling technique maintained constant gas target concentrations during sampling (<4.3% for ethylene, <2.1% for SO2).
• The integrated method successfully quantified trace ethylene and SO2 in real fruit samples with good accuracy.
• High recovery rates were achieved, ranging from 95.0-101% for ethylene and 97.0-104% for SO2.

Conclusions:

• The portable LVCC sampling technique coupled with SERS provides a rapid and accurate method for on-site trace gas analysis.
• This approach offers a representative sampling strategy, overcoming limitations of traditional methods.
• The developed technique holds significant potential for advancing field analysis of trace gases in various real-world samples.