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...

A 5-amino-8-hydroxyquinoline (AHQ)-modified gold nanoparticle (GNP) layer was fabricated on an inner wall of a silica capillary column by alternatively passing a citrate-stabilized GNP solution and an AHQ solution in a repeating fashion. The observations by a field emission scanning electron microscope showed that the thickness of the resulting GNP layer was about 0.15 microm. This column was t...

a rapid and reproducible method is described that employs solid phase extraction (spe) using dichloromethane, followed by gas chromatograph-mass spectrometry for the determination of toxic toluene, xylene and cumene (txc) from different lake water of dhaka mega city of bangladesh. the method was applied to detect and quantify txc in water samples collected from surface and 30 cm depth of water....

A commercial pharmaceutical analysis chiral method development kit (Chirex Column Kit A, Phenomenex) was used to analyze six pesticide stereoisomer mixtures. The pesticides were selected from the 1994-1995 National Water Quality Assessment Program (NAWQA) covering New Mexico and Texas. Three stereoisomer mixtures were separable on three different columns. The instrumental detection limit and de...

A new column packing, SP-2510 DA (Supelco, Inc., Bellefonte, Pa. 16823), is an excellent stationary phase for the determination of a wide variety of anticonvulsant drugs by gas--liquid chromatography without derivatization. However, when uncomplicated extraction procedures are used, serum cholesterol interferes with the determination of primidone. By the simple expedient of adding a short "pre-...

The mass transfer performance of a pulsed disc and doughnut column for extraction of samarium and gadolinium from aqueous nitrate solution with D2EHPA was investigated. The effects of operating parameters such as pulsation intensity, continuous and dispersed phase velocities on column performance were investigated. The axial dispersion model was used to obtain the overall mass transfer coef...

We describe a routine method for determining plasma concentrations of quinidine by liquid chromatography. The procedure requires 1.0 ml of plasma (or serum) and involves internal standard addition, extraction with ether, and separation on a column of microparticulate silica. Day-to-day CV (15 days) was less than 5% and no deterioration in column performance has been observed during 12 months. C...

Sulfonamides were extracted from honey with acetate buffer (pH 5.0), and cleaned up by solid phase extraction (SPE) procedure. The liquid chromatography (LC) separation was carried out on RP C18 column using acetic acid and acetonitrile as the mobile phase in gradient mode and monitored with fluorescence detector, after pre-column derivatisation. Recoveries from spiked honey were above 80%, and...