Direct determination of bisphenol A and nonylphenol in river water by column-switching semi-microcolumn liquid chromatography/electrospray mass spectrometry 

Rapid Communications in Mass Spectrometry v.13, i.21, 1999. Pages: 2204-2208

Article Abstract

Akira Motoyama 1 *, Ayako Suzuki 2, Osamu Shirota 2, Ryujiro Namba 1 1Analytical Research Division, Pharmaceutical Research Laboratories, Shiseido Co., Ltd., 2-12-1 Fukuura, Kanazawa-ku, Yokohama 236-8643, Japan 2Shiseido Research Center, 1050 Nippacho, Kohoku, Yokohama 223-8553, Japan

*Correspondence to Akira Motoyama, Analytical Research Division, Pharmaceutical Research Laboratories, Shiseido Co., Ltd., 2-12-1 Fukuura, Kanazawa-Ku, Yokohama 236-8643, Japan 

Abstract
A rapid and sensitive analytical method based on column-switching semi-microcolumn high-performance liquid chromatography (HPLC) with electrospray mass spectrometry was developed for determining trace levels of bisphenol A (2,2-bis(4-hydroxyphenyl)propane) and nonylphenol (4-nonylphenol) in river water. An aliquot of sample solution was directly injected into the precolumn packed with Capcellpak MF-Ph for sample cleanup and enrichment. The compounds of interest were then transferred to a C-18 analytical column for main separation through a change in flow path by a programmed switching valve. Bisphenol A, nonylphenol, and interfering substances were satisfactorily separated with a simple gradient elution complete within 35 min. Detection of their deprotonated molecules was conducted in negative ion mode. A reduced flow rate (100 µL/min) optimized for the narrow bore column was found advantageous in obtaining a high degree of sensitivity during electrospray detection. The influence of carrier additives on sensitivity was also examined. This method produced detection limits of 0.5 ng/mL for bisphenol A and 10 ng/mL for nonylphenol (signal-to-noise ratio 3). Calibration curves were observed in the range of 2.5-50 ng/mL (r2 = 0.999) for bisphenol A and 50-500 ng/mL (r2 = 0.998) for nonylphenol. Recoveries of the compounds from spiked distilled water and river water were 99.7-138.5% with a relative standard deviation (RSD) ranging from 2.2-9.7%. 

Received: 9 August 1999; Revised: 10 September 1999; Accepted: 12 September 1999