包裝飲用水中鄰苯二甲酸二（2-乙基己基）酯之檢驗研究

Investigation of Test Method for Di (2-ethylhexyl) phthalate Residue in Bottled Water

鄰苯二甲酸二（2-乙基己基）酯（di（2-ethylhexyl）phthalate, DEHP）為廣泛使用的塑化劑之一，用以增加塑膠材質的彈性。但消費者對於DEHP是否會自食品容器中溶出，因而造成危害之風險仍有疑慮。國際癌症研究署（International Agency for Research on Cancer, IARC）將DEHP歸為2B級可能致癌物（possibly carcinogenic to humans）。106年消費者文教基金會進行高溫環境下儲存後包裝飲用水之DEHP溶出試驗並發布新聞指出，食藥署公開之食品中鄰苯二甲酸酯類檢驗方法之定量極限（limit of quantification,LOQ）高於國際標準，無法判定瓶裝水於高溫儲存後DEHP溶出之結果。因目前公開之建議檢驗方法適用範圍為食品基質之塑化劑檢測，定量極限訂定為0.05 mg／kg，故需開發適用於包裝飲用水之DEHP之檢驗方法。本研究參考「食品中鄰苯二甲酸酯類塑化劑檢驗方法」，取去離子水製備標準曲線，線性範圍為2－50ng／mL，並調整內標添加量，搭配液相層析串聯質譜儀（liquid chromatograph／tandem mass spectrometer,LC／MS／MS）進行分析。添加回收試驗為於去離子水中添加0.002及0.005 mg／L之標準品，其平均回收率分別為98.4及98.0％；去離子水中添加0.002 mg／L標準品之同日與異日變異係數分別為5.6及5.4％，顯示方法之準確度與重複性皆良好，本方法之定量極限為0.002 mg／L。以建立之方法檢測10件市售包裝飲用水，其包裝材質皆為PET，分別儲藏於室溫與高溫（50或60°C）7日，於儲藏前與儲藏第1、4及7天取樣分析，結果皆未檢出DEHP。 Di (2-ethylhexyl) phthalate, also called DEHP, is used worldwide as a plasticizer to increase the flexibility of plastics. Because of the possible migration of DEHP from plastic package toward other media kept in contact such as food, consumers may expose to this harmful chemical. DEHP is classified into Group 2B (possibly carcinogenic to humans) by IARC. Recently, Consumers' Foundation, Chinese Taipei (CFCT) suggested a lower limit of quantification (LOQ) for the testing method of DEHP in bottled water, because the current method, ＂Method of Test for Phthalates Plasticizers in Foods＂ offered a higher LOQ than international drinking water regulations. Therefore, this study aimed on developing a new detection method of DEHP in water and conducting a survey on the migration of DEHP from the plastic package of bottled water toward its media, water. Particularly, for the bottled water exposed to high temperature. The current method was modified to the calibration range of 2 - 50 ng/mL by adding the standard to deionized water. Moreover, isotopic internal standard DEHP-d_4 was applied. The LC/MS/ MS testing method of DEHP in water was validated through the following testing. A recovery study for DEHP was done at spiked levels of 0.002 and 0.005 mg/L in deionized water. The average recoveries were obtained as 98.4 and 98.0%, respectively. The coefficients of variation (CV) in repeatability and intermediate precision were 5.6 and 5.4%, respectively. The above results showed this method performed well in accuracy and precision. LOQ was assigned to 0.002 mg/L. In the surveillance study, ten brands of PET-bottled water were purchased. Two samples for each brand were stored at room temperature or higher temperature for seven days, respectively. The results showed that all samples were not detected during the 7-days storage period.