Journal of Chromatography A, 895 (2000) 213–218 www.elsevier.com / locate / chroma Separation of bisphenol A and three alkylphenols by micellar electrokinetic chromatography a, b b b c a,b * S. Takeda , S. Iida , K. Chayama , H. Tsuji , K. Fukushi , S. Wakida a Department of Energy and the Environment, Osaka National Research Institute, AIST, MITI,1-8-31, Midorigaoka, Ikeda, Osaka 563-8577, Japan b Department of Chemistry, Faculty of Science, Konan University,8-9-1, Okamoto, Higashinada, Kobe 658-8501, Japan c Research Institute for Marine Cargo Transportation, Kobe University of Mercantile Marine,5-1-1, Fukaeminami, Higashinada, Kobe 658-0022, Japan Abstract Analytical conditions of pH, surfactants, and additives were investigated for the simultaneous separation of bisphenol A and alkylphenols by micellar electrokinetic chromatography. Reproducibility of migration time was improved at higher pH (pH 8.0). When five surfactants having linear alkyl chains or four bile salts were used, the separation of hydrophobic phenols and 4-nonylphenol isomers was not achieved. In order to improve the separation, the use of additives with sodium dodecyl sulfate solution was investigated. The separation of hydrophobic phenols was improved by the addition of organic solvents, however, isomers were not separated. Their separation was achieved by the addition of b- or g-cyclodextrin.  2000 Elsevier Science B.V. All rights reserved. Keywords: Buffer composition; Alkylphenol; Phenols; Bisphenol A 1. Introduction Bisphenol A (BPA) and alkylphenols (4-substi- tuted, carbon number: 4|9) are listed in SPEED ’98. Recently, several chemicals are suspected that They are consumed in large volume for industrial they have endocrine disrupting effects [1]. The use. Four of them, BPA, 4-tert.-butylphenol (4-tBP), Environmental Agency of Japan arranged ‘‘Strategic 4-(1,1,3,3-tetramethylbutyl)phenol (4-tOP) and 4- Programs on Environmental Endocrine Disruptors nonylphenol (4-NP) have relatively high detection ’98’’ (SPEED ’98) in May, 1998 [2]. In the pro- frequency from environmental waters in Japan [3]. grams, sixty-seven suspected chemical groups are BPA is mainly used for the production of polycarbo- listed. For the accurate assessment of human expo- nate or epoxy resin [4]. 4-NP are the raw material of sure of these chemicals, development of their easy nonylphenol polyetoxylates, those are widely used analytical methods was very important. At present nonionic surfactants and used as the complex of gas chromatography–mass spectrometry (GC–MS) branched sidechain isomers [5]. The regulated is mainly regulated as their analytical method. analytical method of BPA and alkylphenols is GC– MS with derivatization because of their polar hy- droxyl groups, however, derivatization procedure is *Corresponding author. complex and time-consuming [6]. 0021-9673 / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0021-9673(00)00666-X