Online in-tube microextractor coupled with UV-Vis spectrophotometer for bisphenol A detection

Abstract

A simple and high extraction efficiency online in-tube microextractor (ITME) was developed for bisphenol A (BPA) detection in water samples. The ITME was fabricated by a stepwise electrodeposition of polyaniline, polyethylene glycol and polydimethylsiloxane composite (CPANI) inside a silico-steel tube. The obtained ITME coupled with UV-Vis detection at 278 nm was investigated. By this method, the extraction and pre-concentration of BPA in water were carried out in a single step. Under optimum conditions, the system provided a linear dynamic range of 0.1 to 100 μM with a limit of detection of 20 nM (S/N ≥3). A single in-tube microextractor had a good stability of more than 60 consecutive injections for 10.0 μM BPA with a relative standard deviation of less than 4%. Moreover, a good tube-to-tube reproducibility and precision were obtained. The system was applied to detect BPA in water samples from six brands of baby bottles and the results showed good agreement with those obtained from the conventional GC-MS method. Acceptable percentage recoveries from the spiked water samples were obtained, ranging from 83–102% for this new method compared with 73–107% for the GC-MS standard method. This new in-tube CPANI microextractor provided an excellent extraction efficiency and a good reproducibility. In addition, it can also be easily applied for the analysis of other polar organic compounds contaminated in water sample.

Keywords:

• Bisphenol A
• online sample preparation
• in-tube microextractor
• polyaniline
• UV-Vis detection.

Acknowledgments

This project was supported by the National Nanotechnology Center (NANOTEC) Thailand (grant number P-09-00501). The Royal Golden Jubilee Ph.D. Program supported by the Thailand Research Fund, Center of Excellence for Innovation in Chemistry (PERCH-CIC), the Commission on Higher Education, Ministry of Education; the Higher Education Research Promotion and National Research University Project of Thailand, Office of the Higher Education Commission; Trace Analysis and Biosensor Research Center, Prince of Songkla University; Department of Chemistry, Faculty of Science and Graduate School, Prince of Songkla University, Hat Yai, Thailand are gratefully acknowledged. Thanks to Dr. Brian Hodgson for assistance with the English.