REGULAR PAPER REGULAR PAPER Removal of Endocrine Disruptors by Selective Sorption Method using Activated Carbons ῐ Boo Ok YDDC, a) Shin KDN6C6<>, a) Takao AH6CD, a) Mariko H6G6, a) and Akon H><J8=>῎ a) (Received September 20, 2002; Accepted October 28, 2002) We undertook a fundamental investigation of the removal of endocrine disruptors from aqueous solution by a sorption method using activated carbons, and compared the removal ability of endocrine disruptors by activated carbons to that by polydimethylsiloxane (PDMS) membranes. The activated carbons exhibited high removal ability of 1,2-dibromo-3-chloropropane (DBCP), 100 fold increased adsorption over that with PDMS membranes from aqueous solution of DBCP. The removal ratio of the endocrine disruptors, e.g., 1,2-dibromo-3- chloropropane, dibenzo-p-dioxin, and hexachlorocyclohexane, increased linearly in an aqueous solution with increasing the logarithm of P ow of the endocrine disruptors. Almost complete removal of the endocrine disruptors (i.e.,῎85῏) was observed above log P ow ῍3.5 in 25 mL of an aqueous solution using 0.05 g activated carbon. One aim of the present study is to use preferential sorption of chemical contaminants onto activated carbons for removal of the chemical contaminants from aqueous solutions including drinking water, beverages, milk, and human milk. When the removal of endocrine disruptors contained in milk or human milk is targeted, water soluble vitamins in the milk, such as vitamin B 2 , vitamin B 12 , and niacin are expected to be co-currently adsorbed on the activated carbons. Therefore, the present sorption method using activated carbon was applied to the removal of endocrine disruptors, such as di-n-octylphthalate, from the mineral water and 89῏ of di-n-octylphthalate was removed. 1. Introduction Endocrine disruptors, such as polychlorinated bi- phenyls (PCBs), dioxins, and certain phthalates exhibit estrogenic activity. 1), 2) They adversely a#ect the de- velopment and reproduction of humans and animals 3)῍5) and thus their presence in the environment is of major concern. In this work, we examined the feasibility of removing endocrine disruptors from aqueous solutions including drinking water, beverages, milk, and human milk by sorption with activated carbons. Activated carbons are adsorbents which are widely used in many processes for gas and water purification. 6) Although activated carbons have been known for a long time for their abilities to adsorb organic com- pounds, there have only been a few reports of the adsorption characteristics of endocrine disruptors by activated carbons. 7), 8) Cheong et al. investigated the adsorption of pesticides such as Fenobucarb (BPMC), Simazine, and Chlorothalonil in aqueous solution onto granular activated carbons and activated carbon fiber. 7) Nakano reported adsorption characteristics of pesticides (i.e., herbicides, insecticides, and bactericide) onto activated carbons, log P ow values of which ranged from 1.65 to 5.01 8) where log P ow is a partition coe$- cient of a substance between water and n-octanol, and a) Department of Applied Chemistry, Seikei University (Mu- sashino 180῍8633, Japan) ῎ Corresponding author. Tel: ῌ81῍422῍37῍3748; Fax: ῌ81῍422῍37῍3871; e-mail: higuchi@ch.seikei.ac.jp exhibits an index of the hydrophobicity of substance. Human milk often contains trace amounts of chemi- cal contaminants known to be endocrine disruptors, e. g., DDT, hexachlorocyclohexane (HCH), polychlo- rinated biphenyls (PCBs), and dibenzo-p-dioxin. 9)῍12) The concentrations of PCBs and dioxins in human milk in some countries are so high that the breast-fed infant’s intake exceeds the TDI (tolerable daily intake). 9)῍13) Human milk has unique nutritional and immunological properties and is the most natural and important food source for infants. There are many advantages to breastfeeding infants based on medical studies, e.g., protection against infectious diseases 1)῍3) and allergies, 4) and enhanced development and intelli- gence. 3) However, no method for removal of endocrine disruptors from human milk has yet been reported. Therefore, a goal of our study is to use preferential sorption of chemical contaminants onto activated car- bons for the removal of the chemical contaminants from aqueous solutions including drinking water, bev- erages, milk, and human milk. Because endocrine dis- ruptors, such as polychlorinated dioxins, DDT, PCBs, and agricultural chemicals, have hydrophobic charac- teristics similar to hydrophobic estrogen, these chemi- cal contaminants are expected to be absorbed from lipid micelles and proteins in the milk onto activated carbons or hydrophobic membranes such as poly- dimethylsiloxane membranes, after these adsorbents come into contact with the aqueous solution or milk containing the chemical contaminants. In this study, ῐ Congratulations on winning the 2002 Nobel Prize Congratulation, Prof. Fenn. I remember I visited Prof. Fenn’s laboratory at Yale university, when Dr Nohmi was proceeding his research at Prof. Fenn’s laboratory. I am happy to hear Prof. Fenn received Novel Prize in 2002. J. Mass Spectrom. Soc. Jpn. Vol. 51, No. 1, 2003 ῌ168 ῌ