Solid-phase extraction using molecularly imprinted polymer for selective extraction of natural and synthetic estrogens from aqueous samples

Abstract

9A method is proposed for the clean-up and preconcentration of natural and synthetic estrogens 10 from aqueous samples employing molecularly imprinted polymer (MIP) as selective sorbent 11 for solid-phase extraction (SPE). The selectivity of the MIP was checked toward several 12 selected natural and synthetic estrogens such as estrone (E1), 17β-estradiol (β-E2), 17α-13 estradiol (α-E2), estriol (E3), 17α-ethinylestradiol (EE2), dienestrol (DIES) and 14 diethylstilbestrol (DES). Ultrahigh pressure liquid chromatography (UHPLC) coupled to a 15 TSQ triple quadrupole mass spectrometry (QqQ) was used for analysis of target analytes. The 16 chromatographic separation of the selected compounds was performed in less than 2 min 17 under isocratic conditions. The method was applied to the analysis of estrogens in spiked river 18 and tap water samples. High recoveries (>82%) for estrone, 17β-estradiol, 17α-estradiol, 19 estriol and 17α-ethinylestradiol were obtained. Lower but still satisfactory recoveries (>48%) 20were achieved for dienestrol and diethylstilbestrol. The method was validated and found to be 21 linear in the range 50-500 ng L -1 with correlation coefficients (R 2 ) greater than 0.995 and 22 repeatability relative standard deviation (RSD) below 8% in all cases. For analysis of 100-ml 23 sample, the method detection limits (LOD) ranged from 4.5 to 9.8 ng L -1 and the limit of 24 quantitation (LOQ) from 14.9 to 32.6 ng L -1 . systems such as UV [7,8], fluorescence [9] and coupled to mass spectrometry [10,11,12,13], 49 gas-chromatography after derivatization [14] and enzyme-linked immunosorbent assay [15]. 50Currently, liquid chromatography coupled with tandem mass spectrometry is the most 51 common approach. However, as the concentrations of the estrogenic compounds in 52 environmental matrices are very low, a clean-up and preconcentration step is usually required 53 in order to minimize interferences and improve method accuracy and sensitivity. Solid-phase 54 extraction (SPE) is a well-established method routinely used for clean-up and 55 preconcentration step of this compounds [16]. The main drawback of conventional SPE 56 sorbents is their lack of selectivity resulting in co-extraction of interfering matrix components, 57 which can negatively affect quantitation. Selectivity can be obtained using sorbents based on 58 molecularly imprinted polymers (MIP). These types of sorbents are synthetic materials 59 possessing an artificially generated three-dimensional network that is able to specifically 60 rebind a target analyte, or class of structurally related compounds. MIP has the advantages of 61 being very selective, cost-effective, and not suffering from storage limitations and stability 62 problems regarding organic solvents. MIPs have been proposed in recent years as sorbent for 63 the extraction and/or removal of endocrine disrupting compounds [17,18,19]. In addition, the 64 potential of MIP as SPE sorbent for extraction of diethylstilbestrol [20,21] Extraction and clean-up using MIP-SPE 129 1...

Dual cloud point extraction coupled with hydrodynamic-electrokinetic two-step injection followed by micellar electrokinetic chromatography for simultaneous determination of trace phenolic estrogens in water samples

“…In SPE, sorbents are required, such as hydrophilic-lipophilic balance sorbents [5,6,8], 17β-estradiol molecularly imprinted polymer [7], bamboo charcoal [9], and functionalized magnetic nanoparticles (Fe 3 O 4 -SiO 2 /β-cyclodextrin core/shell) [10,11]. Besides, in methods such as SPE-HPLC and solid-phase microextraction-HPLC, complex enrichment procedures [5][6][7][9][10][11], time-consuming procedures [9][10][11][12], rigorous detection methods [5][6][7], and high cost [5][6][7][9][10][11] are also involved. Although HPLC has often been used for the determination of PEEs, CE is also used.…”

“…Nowadays, various methods are available for the determination of PEEs, such as solid-phase extraction (SPE)-ultraperformance liquid chromatography [5][6][7], solid-phase microextraction-high performance liquid chromatography-(HPLC) mass spectrometry-tandem mass spectrometry [8], SPE-HPLC [9][10][11], and capillary electrophoresis (CE) [12,13]. In SPE, sorbents are required, such as hydrophilic-lipophilic balance sorbents [5,6,8], 17β-estradiol molecularly imprinted polymer [7], bamboo charcoal [9], and functionalized magnetic nanoparticles (Fe 3 O 4 -SiO 2 /β-cyclodextrin core/shell) [10,11].…”

Current Trends in Sample Treatment Techniques for Environmental and Food Analysis

“…It should be pointed out, however, that in some cases this selective washing step can be problematic because of the low polarity of common solvents used, which may give rise to miscibility problems and/or losses of the analyte [54]. Consequently, a drying step prior to this organic washing process becomes mandatory [8].…”

“…Nevertheless, sorbents used in conventional SPE often lack selectivity resulting in co-extraction of interfering matrix components. Therefore, specificity, selectivity and sensitivity together with high extraction efficiency can be obtained using sorbents based on molecularly imprinted polymers (MIPs) [8].…”

“…Consequently, in order to minimize the effect of all these possible interferences a selective clean-up step may be required. Higher specificity and selectivity together with satisfactory extraction efficiency can be obtained using sorbents based on molecularly imprinted polymers (MIPs) [6][7][8].…”