Assay of endocrine disruptors in store daily dishes and alteration in their concentration by microwave cooking.

2003 Fiscal Year Final Research Report Summary

• Project/Area Number: 14580137
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 食生活
• Research Institution: Ochanomizu University
• Principal Investigator: TOMINAGA Noriko Ochanomizu University, Center of environmental science for human life, Professor, 生活環境研究センター, 教授 (30164031)
• Project Period (FY): 2002 – 2003
• Keywords: Bisphenol A / Nonylphenol / Phthalate esters / Store daily dishes / Plastic container / Migration / Endocrine disruptor

Research Abstract

Although the great portion of endocrine disruptors (bisphenol A, 4-nonylphenol, and phtalate esters) in the living body are said to be taken from foods., there are few measurements of their concentrations in diet by present. Daily dishes in plastic containers are incleasing sales and warming up in many cases. The concentrations of endocrine disruptors in them was measured at the time of purchase and after microwave cooking.
1)Phthalate esters : Extraction and purification were carried out according to the modified the method of Society of Environmental Science, Japan. Identification was performed by GCMS and measurement by reversed-phase HPLC. Dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP) were always detected among six kinds of phtalate esters. It was reflected the present amount used in our country. The contents hardly changed by microwave cooking, or their values after cooking were lower in many cases. This was considered because the volatility of phthalate esters is high. When a food was wrapped in the lap more tightly and heated, the phthalate esters which once volatilized tended to return with steamy condensation again.
2)Bisphenol A : Extraction and purification were carried out by the method of Tsuda, T.et al., J.Chromatogr.B, 723, and 273 (1999), and then Identification and measurement were performed by GCMS. The concentrations of bisphenol A in dishes cooked using oil and fats were higher clearly than those of containing low oil. Therefore, it was suggested that this chemical shifts to oil and fats and fatty foods. Although the upward tendency of a content by heating was observed, since the difference among the kinds of daily dishes were larger than by heating, it was thought that shift took place from a container to food also under low temperature or normal temperature.
3)4-Nonylphenol : it was extracted simultaneously with bisphenol A, separated during purification, and measured in GCMS. However, impurities could not be removed and a detectable peak was not identified. In order to gather extraction efficiency and to raise the degree of purification, the preparation of the sample solution in another method was tried, but remarkable results were not obtained.