Biomonitoring of phthalate esters in breast-milk and urine samples as biomarkers for neonates' exposure, using modified quechers method with agricultural biochar as dispersive solid-phase extraction absorbent

Abstract

Phthalates are known hepatotoxins and carcinogens besides being endocrine disruptors with a possible link to adverse reproductive and neuro-developmental outcomes. Their use in diverse industrial, consumer and personal care products resulted in widespread exposure of the human population, particularly vulnerable groups including pregnant women and infants. This study focused on the assessment of the levels of phthalates in the breast-milk and urine samples of lactating mothers using a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) technique. The extracts obtained with acetonitrile solvent were purified using agricultural materials (spent seedcake of Calophyllum inophyllum, coconut husk (Cocos nucifera) and Moringa oleifera seeds) as dispersive solid-phase extraction (d-SPE) absorbents before gas chromatography analyses. The method's performance in terms of purification efficiency and recovery were evaluated before applying the method for the extraction of phthalates from breast-milk and urine samples.Calibration curves for all the phthalates determined showed correlation coefficients better than 0.99 with detection limits ranging from 0.012 to 0.020 µg/L. The proposed method showed satisfactory recoveries at two fortification levels (5 µg/L & 100 µg/L) with the least recovery being 83% with good precision indicated by relative standard deviations < 20%. The results showed significant correlations between bis (2-ethylhexyl) phthalate (BEHP) levels in Breast-milk and medication use, intravenous transfusion and caesarean mode of delivery. Diethyl phthalate (DEP) in urine correlated significantly with the use of cosmetics and personal care products. The high concentration of phthalates in nursing mothers' breast-milk may be an indication of neonates exposure to the chemical.