PET包裝飲用水中銻溶出之溫度儲藏試驗   全文下載

Test for Antimony Migration in PET-Packed Drinking Water at Different Storage Temperature

聚對苯二甲酸乙二酯（Polyethylene terephthalate, PET）具質輕、韌性佳及方便攜帶等優點，常作為飲用水盛裝容器。三氧化二銻（Antimony trioxide）被廣泛用作生產PET的聚合反應之催化劑，故PET容器於儲存過程中，可能因溫度、pH或PET降解等影響而釋出銻於飲用水中。衛生福利部（下稱衛福部）於「食品中污染物質及毒素衛生標準」訂定PET包裝飲用水中銻之限量為0.01 mg/kg。為了解PET包裝飲用水於不同儲藏環境下銻溶出情形，本研究挑選10種市售PET包裝飲用水產品，分別置於室溫、50℃及60℃環境儲存，並比較儲存第0、1、4、7天及1個月之銻溶出量，另取1件PET包裝飲用水存放於室溫且讓其超出保存期限後檢測銻溶出量。本研究依據衛福部公告之「包裝（盛裝）飲用水及食用冰塊中重金屬檢驗方法（MOHWH0022.00）」進行銻含量測定，並於每次試驗搭配試劑空白、添加回收試驗及參考物質驗證以確保試驗品質。試驗結果顯示，除1件檢體於有效儲存期內銻未檢出外，其餘檢體中銻溶出量皆隨著儲藏溫度及時間增加而增加：室溫、50℃及60℃環境中，銻溶出量隨時間變化分別為：未檢出-0.0017 mg/kg、未檢出-0.0044 mg/kg及未檢出-0.0108 mg/kg，另觀察1件檢體超出保存期限之PET包裝飲用水中銻為未檢出。值得注意的是，其中1件檢體於60℃儲藏1個月，其銻溶出量已達法規限量。根據試驗結果，PET包裝飲用水應避免長期存放於高溫環境中，以降低PET溶出銻之風險。

Polyethylene terephthalate (PET) material is lightweight, tough and portable thus often made into containers for drinking water. As antimony trioxide is widely used as a polycondensation catalyst in PET production, antimony may slowly migrate into drinking water due to the effects of temperature, pH or the degradation of PET containers during storage. The Ministry of Health and Welfare in Taiwan stipulates the maximum level of antimony in drinking water packed in PET containers as 0.01 mg/kg under the“Sanitation Standard for Contaminants and Toxins in Food”. To understand the leaching of antimony in PET-packed drinking water under different storage temperature, ten commercially available PET-packed drinking water products within the expiration date were selected, stored at room temperature, 50℃, or 60℃, and the migration amount of antimony at 0 day, 1st day, 4th day, 7th day and 1 month of storage duration measured. Also another PET-packed drinking water product was stored at room temperature until past the expiration date then the migration amount of antimony measured. The migration amount of antimony in PET-packed drinking water was determined according to the“Method of Test for Heavy Metals in Bottled (Packaged) Drinking Water and Ice Cubes (MOHWH0022.00)”announced by the Ministry of Health and Welfare. Quality controls carried out for each batch test included a reagent blank, a spiking recovery test, and confirmation of the reference material. The results showed that except for one sample in which antimony was not detected at the tested range of different temperature and duration, the migration amount of antimony in the rest of the samples increased with the increase of storage temperature and time. At room temperature, 50℃, and 60℃, the migration amounts of antimony ranged from ND to 0.0017 mg/kg, ND to 0.0044 mg/kg, and ND to 0.0108 mg/kg, respectively. Antimony in the PET-packed drinking water over the expiration date was not detected. It is worth noting that one of the samples was observed the migration of antimony amount exceeded the regulation limit when stored at 60℃for one month. According to the results, long-term storage of PET-packed drinking water in high-temperature environment should be avoided to reduce the risk of antimony migration from PET containers into drinking water.