Simultaneous determination of isoflavones and lignans at trace levels in natural waters and wastewater samples using liquid chromatography/electrospray ionization ion trap mass spectrometry

Abstract

A high-performance liquid chromatography/electrospray ionization ion trap mass spectrometry (HPLC/ESI-MSn) method has been developed for the trace determination of phytoestrogens in aquatic environmental samples. The method includes solid-phase extraction (SPE) and analysis using liquid chromatography/electrospray ionization ion trap mass spectrometry. The aquatic environmental samples, influent of a wastewater treatment plant (WWTP) and creek water, were adjusted to pH approximately 5 before extraction. The analyzed phytoestrogens were identified by an MSn method and quantified against a deuterated internal standard (genistein-3',5',6,8-D4). In negative ion mode, 0.1% formic acid was employed in acetonitrile/water mobile phase. The method detection limits ranged from 0.5 to 10 ng/L in WWTP influent and from 0.1 to 5 ng/L in creek water. Average SPE recoveries for the analyzed phytoestrogens ranged from 85 to 95%, with a relative standard deviation (RSD) (%) ranging from 3.9 to 6.5. The concentrations of the six analyzed phytoestrogens varied from 0.2 to 600 ng/L with high levels of enterolignans (enterolactone and enterodiol) found in the collected wastewater. The method is shown to be suitable for the determination of phytoestrogens in aquatic environmental samples at nano- and sub-nanogram per liter levels.

Occurrence of “mammalian” lignans in plant and water sources

“…In our HPLC-MS/MS analyses, we discovered that the HPLC eluent water contained EL although it had been produced by processing deionised tap water through a water puriWcation system (Saarinen et al 2002b;Smeds and Hakala 2003). Our Wndings on the presence of EL in water were very recently conWrmed in a study by Kang et al (2006). They detected ED and EL in wastewater treatment plant inXuent and in creek water.…”

“…HEL has probably been metabolized from HMR, which is present in cereals, nuts, and oilseeds (Smeds et al 2007). Very recently, the enterolignan content of aquatic environment samples was reported for the Wrst time (Kang et al 2006). The EL concentration was 5 ng/l (0.017 nM) in creek water and 600 ng/l (2.0 nM) in wastewater treatment plant inXuent; both values are about half of the concentrations we found in humic water and in STP inXuent, respectively ( Table 1).…”

Rejection and adsorption behaviour of phytoestrogens by nanofiltration and reverse osmosis membranes

“…This method was adapted from previous reports [5]. Calibration standards (0, 5, 10, 25, 50 and 100 μg/L) were prepared and analysed in background buffer solutions at each appropriate pH value.…”

“…Lundgren and Novak [4] found that the concentration of phytoestrogens in industrial effluent can be much higher (up to 250 μg/L). Genistein, formononetin, biochanin A, daidzein and coumestrol are the most commonly identified phytoestrogens in the aquatic environment, and they have been found in rivers in Australia, Germany and Italy ranging from 1 to 10 ng/L [2,5]. Daidzein and genistein have been detected in river water in Japan at 43 μg/L and 143 μg/L, respectively [6].…”

GC–MS–MS for the Analysis of Phytoestrogens in the Environment

“…However, plant phytoestrogens have been also cited as possible endocrine disruptors in fish along with synthetic hormones and human estrogens from wastewater effluents [8]. Previous studies have found concentrations of biochanin A, daidzein, formononetin, and coumestrol ranging from 1 to 10 ng/L in rivers in Australia, Germany, and Italy [10][11][12][13], whereas 43 mg/L daidzein and 143 mg/L genistein were detected in a Japanese river [8], perhaps because of higher soy impact. Because phytoestrogens are excreted, not only by plants but also by humans and livestock via food consumption, it is important to evaluate their sources in food and their concentration in surface water and wastewater.…”