Assessment of drinking water and beverages and development of an enzyme based biosensor for detection of phthalate esters

Abstract

Phthalate esters are dialkyl or alkylaryl esters of phthalic acid used most commonly as modulators or plasticizers in the manufacture of plastics. The concern of PE leaching from PVC and other plastic products arrives from the fact that PEs are not covalently bond to the polymers and readily leach into the newlinemedium. The most predominant PE that occupy 50% of the total weight of plastic products is DEHP, a high molecular weight PE. Consumption of PET bottled drinking water has been consistently increasing worldwide; this in turn switches on the alarming rate of endocrine disruption among consumers, newlineirrespective of age. Di (2-ethylhexyl) phthalate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, butyl-benzyl phthalate and di-n- octyl phthalate are listed to be the six priority pollutants among PEs causing endocrine disruption by US EPA. Maximum contamination limit of DEHP is 6 ppb according to US newlineEPA Safe Drinking Water Act. Endocrine disruption of PEs tends to associated with increased sperm DNA damage, sex hormone alteration, obesity, decreased pulmonary function, endometriosis, breast cancer, hyperprolactinemia, uterine leiomyomas and thyroid hormone alteration. In the present research work, leaching of PEs into PET bottled medium such as drinking water, soft drinks and beverages were considered to be one among the main source of exposure to PEs. Thus, research work has been conducted to assess the concentration of PE leaching from PET/plastic containers into the medium at varied temperature, pH and storage time. This was followed by designing an enzyme based biosensor for the detection of PEs newlinein drinking water, soft drinks and beverages. In order to use PE specific enzyme, esterase enzyme was isolated and purified from bacterial strain capable of hydrolysing DEHP efficiently. newline newline