College of Natural and Applied Sciences

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Browsing College of Natural and Applied Sciences by Subject "Acataldehyde"

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    Levels of formaldehyde and acetaldehyde in selected bottled drinking water sold in urban areas in Tanzania
    (University of Dar es Salaam, 2014) Mwankuna, Christopher
    This study aimed at determining the levels of formaldehyde and acetaldehyde in bottled drinking water and evaluating the effect of storage time and storage conditions on levels of these aldehydes. A total of 144 samples composed of six brands of bottled drinking water were purchased from four regions (Dar es Salaam, Iringa, Mwanza and Arusha). The samples were analysed on the 1st day and after 14 and 42 days of storage in a refrigerator, at room temperature and exposure to sunlight. The levels of formaldehyde and acetaldehyde in the samples stored in a refrigerator ranged from 2.46 to 19.25 μg/L and from not detected (ND) to 58.70 μg/L, respectively. For the samples stored at room temperature, the levels of formaldehyde and acetaldehyde ranged from ND to 23.26 μg/L and from ND to 36.10 μg/L, respectively. For the samples exposed to sunlight, the levels of formaldehyde and acetaldehyde ranged from 2.46 to 45.96 μg/L and ND to 186.96 μg/L, respectively. Generally, the levels of both formaldehyde and acetaldehyde were found to be lowest for the samples stored in a refrigerator and highest for those exposed to sunlight as compared to samples stored at room temperature. For a particular condition of storage, generally, the levels of both formaldehyde and acetaldehyde increased with increased storage time. The physical parameters of the bottled drinking water (pH, EC and TDS) varied from brand to brand due to the source of water, where they originate and had significant correlation with the concentrations of formaldehyde only in the 1st day analysis. The concentrations of acetaldehyde had negative significant correlation with both EC and TDS, while pH had no significant correlation with the concentrations of acetaldehyde. The levels were below the WHO acceptable limits; however, the findings indicate that the levels could be elevated with increased storage time and exposure to sunlight.