Abstract
Polyethylene terephthalate (PET) is widely used as a raw material for water bottles. However, since PET is an ester, water can react with it to release toxic molecules such as formaldehyde. This work provides a quantitative analysis, by high-performance liquid chromatography (HPLC–UV–Vis) after derivatization with dinitrophenylhydrazine (DNPH) of formaldehyde (FA) in flat natural or carbo-gaseous mineral waters bottled coming from different regions of Morocco, bought at Oujda in a local supermarket and analyzed in the Université of Oujda. At 18 °C, formaldehyde was not detected in 9 of the 12 bottles purchased at the supermarket. For bottles of flat natural mineral water incubated at 30 °C, FA concentrations were below the detection limit, reaching 0.38 µg/L in carbo-gaseous mineral water. At 40 °C, the concentration range was from 12.9 µg/L for flat natural to 31.5 µg/L for carbo-gaseous minerals water. After a 24-month storage at room temperature and away from light, flat natural mineral waters showed traces of FA, and in carbo-gaseous mineral water, the concentration of FA could reach 13.9 µg/L. The results show that temperature, storage duration, and the presence of CO2 influence the migration of formaldehyde from PET, but the rate of migration does not pose a threat to consumer health. Statistical parameters validating the analytical method used are presented with accuracy and precision. The repeatability of several stability statistics of the analytical technique was evaluated.