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Microcystins (MCs), a group of cyclic heptapeptide heaptoxins and tumor promoters, are generated by cyanobacteria occurring in surface waters, such as eutrophic lakes, rivers, and reservoirs. In this present study, a novel double-sided magnetic molecularly imprinted polymer modified graphene oxide (DS-MMIP@GO) based magnetic solid-phase extraction (MSPE) method was developed for fast, effective and selective enrichment, and recognition of trace MCs in environmental water samples combined with high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The synthesized novel DS-MMIP@GO was used as the adsorbents in this work and was carefully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectra. The adsorption and desorption conditions of DS-MMIP@GO toward MCs were optimized in detail to obtain the highest binding capacity, selectivity, and release efficiency. Under the optimum conditions, the enrichment factors of the method for eight target MCs were found to be 2000. The limits of quantitation (LOQs) of the method for eight MCs were in range of 0.1-2.0ngL(-1). The double-sided MMIP modified structure provided DS-MMIP@GO with abundant adsorption sites and permitted it to exhibit excellent enrichment and selectivity toward trace-level MCs. The proposed method was successfully applied for the analysis of environmental water samples with recoveries ranging from 84.1 to 98.2%. Compared to conventional methods for MCs detection reported in literatures, the one developed in this work based on DS-MMIP@GO and LC-MS/MS showed much faster, more sensitive, and more convenient.

A novel planar-structure amine-functional magnetic polymer modified graphene oxide nanocomposite (NH2-MP@GO) was synthesized. The properties were characterized by transmission electron microscopy (TEM) and Fourier-transform infrared spectrometry (FTIR). The obtained adsorption results showed that the NH2-MP@GO had great adsorptive ability toward five chlorophenols (CPs), including 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP). Based on these, an effective magnetic solid-phase extraction (MSPE) procedure coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the preconcentration and determination of the five CPs in environmental water samples was developed. Various experimental parameters that could affect the extraction efficiencies had been investigated in detail. Under the optimum conditions, the enrichment factors of the method for the target CPs were found to be 1000. The proposed method was successfully applied for the analysis of environmental water samples with recoveries ranging from 86.4 to 99.8% with correlation coefficients (R) higher than 0.9994. Good linearities were obtained ranging from 10 to 500ng/L for 2-CP, 5 to 500ng/L for 2,4-DCP, 2 to 500ng/L for 2,4,6-TeCP and 2,3,4,6-TeCP, and 1 to 500ng/L for PCP, respectively. The limits of quantitation for the five CPs were 0.6-9.2ng/L. It was confirmed that the planar-structure NH2-MP@GO was a kind of highly effective MSPE materials used for the trace CPs analyses.

A novel amphiphilic polymeric ionic liquid membrane containing a hydrophilic bromide anion and a hydrophobic carbonyl group was synthesized in dimethylformamide (DMF) systems using the ionic liquid 1-butyl-3-vinylimidazolium bromide (BVImBr) and the methylmethacrylate (MMA) as monomers. The prepared amphiphilic ploy-methylmethacrylate-1-butyl-3-vinylimidazolium bromide (MMA-BVImBr) was characterized by a scanning electron microscope and an infrared spectrum instrument. The results of solid-phase micro-extraction membrane (SPMM) experiments showed that the adsorption capacity of membrane was about 0.76μgμg(-1) for aniline. Based on this, a sensitive method for the determination of trace aniline, as a degradation product of azo dye Orange G under sonication, was developed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The calibration curve showed a good linearity ranging from 0.5 to 10.0μgL(-1) with a correlation coefficient value of 0.9998. The limit of quantification was 0.5μgL(-1). The recoveries ranged from 90.6% to 96.1%. The intra- and inter-day relative standard deviations were less than 8.3% and 10.9%. The developed SPMM-LC-MS/MS method was used successfully for preconcentration of trace aniline produced during the sonication of Orange G solution.

a b s t r a c t A novel, simple and sensitive method was developed for the simultaneous determination of 22 sulfona- mides (SAs) in chicken breast muscle by using the dispersive micro-solid-phase extraction (d-� -SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS). The excellent core-shell nanoring amino-functionalized superparamagnetic molecularly imprinted polymer (CS-NR-Mag-MIP) was used as sorbent, and the main factors affecting the extraction efficiency were investigated in detail. All target compounds showed good linearities in the tested range with correlation coefficients (r) higher than 0.9980. The mean recoveries were in the range of 85.0-112.2% at low, medium and high concentration levels (0.1, 1.0 and 5.0 ng/g). The intra-day and inter-day relative standard deviations (RSDs) were lower than 6.0% and 8.9%, respectively. The limits of quantification for the 22 SAs were between 0.013 and 0.099 ng/g. The developed d-� -SPE-UFLC-MS/MS method had been successfully applied to the chicken breast muscle samples for food-safety risk monitoring in Zhejiang Province, China. The results showed sulfamethazine, sulfamethoxazole and sulfaquinoxaline in five out of three hundred collected samples were detected with concentrations of 0.418-2.28, 16.4 and 2.93 ng/g, respectively. It was confirmed that the CS-NR-Mag-MIP was a kind of highly effective d-� -SPE materials used for the SAs analyses.

A novel, simple and sensitive method based on the use of magnetic dispersive solid-phase extraction (M-dSPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC–MS/MS) was developed to determine seven synthetic pigments (tartrazine, amaranth, carmine, sunset yellow, allura red, brilliant blue and erythrosine) in wines and soft drinks. An amino-functionalized low degrees of cross-linking magnetic polymer (NH 2 -LDC-MP) was synthesized via suspension polymerization, and characterized by transmission electron microscopy (TEM). The NH 2 -LDC-MP was used as the M-dSPE sorbent to remove the matrix from the solution, and the main factors affecting the extraction were investigated in detail. The obtained results demonstrated the higher extraction capacity of NH 2 -LDC-MP with recoveries between 84.0 and 116.2%. The limits of quantification (LOQs) for the seven synthetic pigments were between 1.51 and 5.0 μg/L in wines and soft drinks. The developed M-dSPE UFLC–MS/MS method had been successfully applied to the real wines and soft drinks for food-safety risk monitoring in Zhejiang Province, China. The results showed that sunset yellow was in three out of thirty soft drink samples (2.95–42.6 μg/L), and erythrosine in one out of fifteen dry red wine samples (3.22 μg/L), respectively. It was confirmed that the NH 2 -LDC-MP was a kind of highly effective M-dSPE materials for the pigments analyses.