ToF‐SIMS mapping of dialkylphthalate and bisphenol‐A adsorbed on small particles

Abstract

AbstractSmall environmental particles are believed to act as carriers of endocrine disrupters so it is very important to establish techniques for analysing such harmful organic species adsorbed on small particles.The authors examined the applicability of time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) for analysis of endocrine‐disrupting chemicals adsorbed on individual small particles in order to evaluate the technique as an environmental analytical tool. Di(2‐ethylhexyl)phthalate (DEHP), dioctylphthalate (DOP) and 2,2‐bis(4‐hydroxyphenyl)propane (bisphenol‐A or BPA) were used as model compounds. All of them are suspected to be endocrine‐disrupting chemicals.First, about one monolayer of each compound was adsorbed on a flat substrate instead of particles, and the mass spectra were measured. Next, DEHP or BPA was adsorbed on 6.8 µm silica particles and ToF‐SIMS spectral mapping was performed. From each spectral map, ToF‐SIMS spectra from a single particle area were extracted.The ToF‐SIMS spectra from actual environmental particles, which adsorb many different kinds of compounds together, are expected to be very much complicated. It seems almost impossible to identify all the compounds. However, if a few expected compounds show strong and characteristic fragment peaks, ToF‐SIMS might be a very powerful tool to analyse the distribution of the compounds. In the study of the fate of endocrine‐disrupting chemicals, very important information such as the relationship between the compound and its carrier particles will be obtained from ToF‐SIMS analysis. Copyright © 2002 John Wiley & Sons, Ltd.