Polymer leachates emulate naturally derived fluorescent dissolved organic matter: Understanding and managing sample...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Spectroscopy

Background:

• Fluorescence spectroscopy is crucial for analyzing dissolved organic matter.
• Sample integrity is vital due to the technique's sensitivity.
• A significant portion of fluorescence sampling uses plastic containers, with many studies not reporting container material.

Purpose of the Study:

• To investigate the potential for plastic sampling containers to leach fluorescent dissolved organic matter (FDOM).
• To assess the impact of these leachates on fluorescence spectroscopy measurements.
• To provide recommendations for best practices in sampling and container selection.

Main Methods:

• Literature survey on container material usage in fluorescence sampling.
• Laboratory investigation of leachate contamination from polypropylene (PP) containers.
• Analysis of leachate characteristics (peaks, concentration) under various conditions (temperature, acidification, sterilization).
• Quantification of potential errors in FDOM measurements due to leachates.

Main Results:

• Polypropylene containers leach characteristic FDOM (Peak T and Peak B) at environmentally relevant levels.
• Leachate intensity increases with higher temperatures, acidification, and steam sterilization.
• Leachates can cause significant errors in FDOM quantification, especially in treated and surface waters.
• PP containers are generally unsuitable for dissolved organic carbon (DOC) measurements.

Conclusions:

• Container material reporting, refrigerated storage, and avoidance of steam sterilization are essential.
• Glass containers are preferred for samples with low FDOM concentrations.
• Plastic-based pollution may be a source of environmentally sampled FDOM, warranting further investigation.