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 evolution of a foam is determined by drainage flow of the continuous (liquid) phase and coarsening (aging) of the dispersed phase (gas bubbles). Free-drainage experiments with slow- and fast-coarsening gases show markedly different dynamics and elucidate the importance of the coupling of the two effects. Strong coarsening leads to drainage times that are shorter (accelerated drainage) and i...

The kinetics of breaking and phenol extraction efficiency the bio-emulsion in liquid-liquid dispersed column are studied by varying bio-surfactant (lecithin) concentration, oil: water ratio, emulsification speed distributor nozzle. Among range parameters studied, maximum 79 % emulsion stability beyond 60 minutes is achieved at optimized conditions. compared with an prepared using Span-80. Even ...

A column of alumina modified with sodium dodecyl sulfate (SDS) and dimethylglyoxime (DMG) was prepared for the preconcentration of trace nickel from water samples for flame atomic absorption spectrometry (FAAS) determinations. Under optimized conditions (pH=7.0; flow rate: 20 mlmin-1) nickel was retained on the column. The nickel collected on the column was eluted with 5 mL of 1 M nitric ac...

In this study the use of particle image velocimetry (PIV) in multiphase ows is described. Velocity elds are measured of both the continuous and the dispersed phase in a bubble column. From the measurements, turbulence characteristics like the strain rate and mutual correlations between gas and liquid velocities can be derived for the validation of numerical simulations.

a column of alumina modified with sodium dodecyl sulfate (sds) and dimethylglyoxime (dmg) was prepared for the preconcentration of trace nickel from water samples for flame atomic absorption spectrometry (faas) determinations. under optimized conditions (ph=7.0; flow rate: 20 mlmin-1) nickel was retained on the column. the nickel collected on the column was eluted with 5 ml of 1 m nitric acid. ...

In the present study, the effect of various nanofluids on mass transfer coefficients in an irregular packed liquid-liquid extraction column was investigated. The chemical system of toluene–acetic acid–water was used. 10 nm SiO2, TiO2 and ZrO2 nanoparticles with various concentrations were dispersed in toluene-acid acetic to provide nanofluids. The influence of concentration and hydrophobicity/h...

urinary 1-hydroxypuren (1-ohp) is commonly used as a major metabolite and biological indicator of the overall exposure to polycyclic aromatic hydrocarbons (pahs). for evaluation of human exposure to such compounds, biological monitoring is an essential process, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to chromatographic techniques. in this...

We have developed a novel solid-phase extraction (SPE) system utilizing a temperature-responsive polymer hydrogel-modified stationary phase. Aminopropyl silica beads (average diameter, 40 - 64 μm) were coated with poly(N-isopropylacrylamide) (PNIPAAm)-based thermo-responsive hydrogels. Butyl methacrylate (BMA) and N,N-dimethylaminopropyl acrylamide (DMAPAAm) were used as the hydrophobic and cat...

The aim of this study is to explore the capability of subcritical methanol to reduce the acidity of naphthenic acids and to determine reaction kinetics for large-scale reactor design.The experiments were carried out in a 25 mL autoclave reactor (China) at temperatures of 70-120oC, Methanol Partial Pressures (MPPs) of 0.1-1.5 MPa, and reaction times of 0-60 min. The total...