A very simple, rapid and sensitive dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography and flame ionization detection (GC-FID) was developed for the determination of phenol and carvacrol in honey samples. A mixture of 100 µl dichloromethane (extraction solvent) and 0.5 ml acetonitrile (disperser solvent) was rapidly injected into sample solution. Thereby a cloudy sol...

abstracta novel floatation-spectrophotometric extraction method was developed for the recovery of tin (ii) from aqueous samples prior to determination by uv spectrophotometric detection. the method is based on the formation of a complex between tin (ii) and kalmagyte in ph=8. the complex is floated in the interface of n-hexane and aqueous phases. after removing the aqueous phase, the floated pa...

in this work, an environmentally friendly sample pre-treatment method, ultrasound assisted surfactant enhanced emulsification microextraction (uaseme) followed with spectrofluorimetry was performed for determination of oxadiazon residues in water samples. after the determination of the most suitable extraction solvent and its volume, other parameters such as type and concentration of surfactant...

Harmonic interference is a major hazard in the current power system that affects quality. How to extract harmonics quickly and accurately premise ensure sustainable operation of system, which particularly important field new energy generation. In this paper, harmonic extraction method based on time-varying observer proposed. Firstly, frequency estimation algorithm used estimate grid frequency, ...

In this article cloud-point extraction (CPE) was used with chelating agent to extract uranium from aqueous solutions. The methodology used is based on the formation of metal complexes soluble in a micellar phase of surfactant. The metal ions complexes are then extracted into the surfactant-rich phase at a temperature above the cloud-point temperature. The effect of type of surfactants and ligan...

This paper sets out the theoretical foundations for continuous-time signal extraction in econometrics. Continuous-time modeling gives an effective strategy for treating stock and flow data, irregularly spaced data, and changing frequency of observation. We rigorously derive the optimal continuous-lag filter when the signal component is nonstationary, and provide several illustrations, including...