a solid phase extraction sorbent based on polyaniline/graphene nanocomposite is presented. the structure and morphology of synthesized nanocomposite were investigated by fourier transform infrared spectroscopy, field emission scanning electron microscopy, x-ray diffraction and thermal gravimetric analysis. the dispersive solid phase extraction was employed to the isolation and preconcentration ...

One of the primary goals of the US Geological Survey (USGS) Laboratory in Lawrence, Kansas, is to develop analytical methods for the analysis of herbicide metabolites in surface and ground water that are vital to the study of herbicide fate and degradation pathways in the environment. Methods to measure metabolite concentrations from three major classes of herbicides--triazine, chloroacetanilid...

Abbreviations: AIBN, 2,20-azo-bis-isobutyronitrile; ASE, Accelerated solvent extraction; CAR, Carboxen; DAD, Diode-array detector; DI-SPME, Direct-immersion solid-phase extraction; DSPE, Dispersive solid-phase extraction; EGDMA, Ethylene glycol dimethacrylate; ESE, Enhanced solvent extraction; ESI, Electrospray ionization; FD, Fluorescence detection; FLD, Fluorimetric detection; GC, Gas chromat...

abstract polycyclic aromatic hydrocarbons (pahs) are classified as persistent and carcinogenic organic pollutants. pahs contamination has been reported in water. many of relevant regulatory bodies such as eu and epa have regulated the limit levels for pahs in drinking water. in this study, 13 priority polycyclic aromatic hydrocarbons (pahs) were determined in tap water samples of tehran and wat...

background and objectives:  high concentration of preservatives in food may result in gastrointestinal disturbances whereby some patients suffering from asthma, rhinitis, or urticaria. the aim of this study is the introduction and optimization a new method for simultaneous determination of four preservatives (sb, ps, mp, pp) in foodstuff by high performance liquid chromatography. materials and ...

Bennett RD and Heftmann E (1962) Thin-layer chromatography of sterols. Journal of Chromatography 9: 359. Copius-Peereboom JW and Beekes HW (1965) The analysis of mixtures of animal and vegetable fats. V. Separation of sterol acetates by thin-layer chromatography in reversed-phase systems and on silica gel G} silver nitrate layers. Journal of Chromatography 17: 99. Hung GWC and Harris AZ (1989) ...

background and objectives: a method was developed and validated for determining 15 polycyclic aromatic hydrocarbons (pahs) in refined olive and refined pomace olive oils using high performance liquid chromatography coupled with a fluorescence detector. materials and methods: the sample preparation involved liquid–liquid extraction with organic solvent and low temperature clean-up. the low tempe...

Poly(L-lactic acid) is a linear aliphatic thermoplastic polyester that can be produced from renewable resources. A poly(L-lactic acid)-modified silica stationary phase was newly prepared by amide bond reaction between amino groups on aminopropyl silica and carboxylic acid groups at the end of the poly(L-lactic acid) chain. The poly(L-lactic acid)-silica column was characterized in reversed-phas...