a simple and mild procedure for the conversion of anilines into aryl isocyanates is described using the 3-hydroxypropylammonium acetate (hpaa) ionic liquid as a novel and efficient media has been explored in the synthesis of aryl isocyanates from the reaction of substituted urea with sodium nitrite in a water immiscible solvent. this ionic liquid can be easily recovered and reused for many time...

In this study, we combined Ionic Liquid-based Dispersive Liquid Liquid Micro Extraction (IL-DLLME) with FAAS for determining the palladium in different real samples at the trace level. 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF6] ionic liquid and 1-(2-pyridylazo) 2-naphthol (PAN), were chosen as the extraction solvent and the chelating agent, respectively. The hydr...

The density (d), speed of sound (u) and electrolytic conductivity (Λ) for systems containing acetaminophen, ionic liquid {1-octyl-3-methyl imidazolium bromide, [OMIm] Br} and water have been measured at T = 293.15-308.15 K. The measured data have been applied to calculate, standard partial molar volume ( ), Hepler’s constant , apparent molar isentropic compressibility...

In this work, a more accurate prediction of liquid evaporation flux has been achieved. The statistical rate theory approach, which is recently introduced by Ward and Fang and exact estimation of vapor pressure in the layer adjacent to the liquid–vapor interface have  been used for prediction of this flux. Firstly, the existence of an equilibrium layer adjacent to the liquid-vapor interface ...

In this work, two approaches based on Dispersive Liquid-Liquid MicroExtraction (DLLME) and Dispersive Liquid-Liquid MicroExtraction based on Solidification of Floating Organic Drop (DLLME-SFO) were compared for the extraction and preconcentration of crocin from saffron and biological samples. Different DLLME and DLLME-SFO parameters influencing the extraction efficiency were studied and opt...

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...

a rapid, simple and sensitive high-performance liquid chromatography method was developed for determination of ciprofloxacin in plasma by means of ultraviolet detection. ofloxacin was used as an internal standard and separation carried on a novapak c18 column using a mobile phase of 0.01 m phosphate buffer (ph =2.6): methanol (82: 18 v/v). extraction of drug was performed from plasma by liquid-...

the present study investigates the performance and relative accuracy of four lattice-hole theory based equations of state in modeling and correlating the liquid density of pure refrigerants. following the gathering of a database of 5740 experimental liquid density datapoints of 36 pure refrigerants belonging to five different categories including cfcs, hcfcs, pfcs, hfcs and hfes, ranging from 6...

a simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]br) under solvent-free conditions is reported. the presented method is benefited from operational simplicity,...