Aldehyde contamination of mineral water stored in PET bottles

Abstract

Aldehyde contaminations that might accompany production of mineral water stored in PET bottles were investigated. One of the production lines of carbonated mineral water in Poland was monitored and PET bottles commonly used for mineral water storage were evaluated. Formaldehyde and acetaldehyde were the most important carbonyls identified in series of bottled water samples, but also propanal, nonanal and glyoxal were found in water samples from the production line. Aldehydes are present everywhere in the environment and can be determined even in pure water at low μg l⁻¹ levels. It was observed that the concentration of acetaldehyde in water stored in PET bottles depended mainly on the concentration of acetaldehyde in PET material and could reach more than 200 μg l⁻¹. The temperature, time of storage and concentration of carbon dioxide gas contribute to the migration of aldehydes from bottle walls to mineral water. Higher pressure of the carbonated waters and not CO₂ itself or lower pH of waters seems responsible for higher concentration of acetaldehyde.

Keywords:

• mineral water packaging
• PET bottles
• PET degradation
• aldehyde migration
• carbonyl compounds

Acknowledgement

The authors acknowledge the financial support of the Polish Committee for Scientific Research (Grant No. 3P06T04024), and thank Z. Zając and U. Zielińska for the analysis of aldehydes in PET material.

Notes

^aNot detected, detection limit 50 ng l⁻¹, number of replicates = 5.