Objective To determine the concentrations of di-ethyl phthalate (DEP), di-n-butyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) in beverages bottled in plastic containers and to analyze the effect of some factors on the concentration of phthalates.
Methods Forty-nine different brands of beverage were selected from the market and gas chromatography was applied to determine the level of phthalates in the beverage. The differences between three sorts of beverages (tea, juice, and dairy drinks) were tested by ANOVA and the effects of storage time and pH value on the concentration of phthalates in beverage were analyzed using Linear Regression Model.
Results DEP wasn't found while the detection rates of DBP and DEHP in samples were 98.0% and 100% respectively with the average concentrations of 0.038 mg/L and 0.071 mg/L respectively. The detection range of DBP and DEHP in tea drinks were 0-0.047 mg/L and 0.045-0.146 mg/L respectively. The highest detection level of DBP in juice drinks was 0.127 mg/L, and DEHP was found in the range from 0.060 mg/L to 0.371 mg/L. The maximum concentrations of DBP and DEHP in dairy drinks were 0.081 mg/L and 0.089 mg/L respectively, and the minimum concentrations were 0.032 mg/L and 0.033 mg/L respectively. The levels of DBP in juice and dairy drinks were significantly higher than those in tea drinks (P=0.003 and P=0.002). The levels of DEHP in juice drinks were higher than those in tea and dairy drinks (P=0.001 and P=0.002). The fixed multivariate linear model showed that, the logarithms of DBP concentrations of juice and dairy drinks were 0.36 and 0.50 units higher than that of tea drinks, the logarithm of DEHP concentration of juice drinks was 0.47 units higher than that of tea drinks, and the logarithm of DEHP concentration of acid drinks was 0.30 units higher than that of weak acid drinks.
Conclusion It can be concluded that the detection rates of DBP and DEHP in plastic bottled beverages were fairly high and their levels varied from the different kinds of drinks. However, the concentrations of phthalates meet the national prescribed standards. The major sources of phthalates in drinks are residues in raw material and migration from plastic bottles. Besides, the level of DEHP would increase with the pH value of drinks decreased.
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