BIS-2-pyridyl glycol as a reagent for gravimetric determination of uranium,aluminium and beryllium

Bis-2-pyridyl glycol has been used for the gravimetric determination of uranium, aluminium and beryllium. The reagent quantitatively precipitates uranium from uranyl nitrate solution at pH 5.0–8.0, aluminium from potash alum solution at pH 5.2–8.5 and beryllium from beryllium sulphate solution at pH 7.5–9.5. The precipitate in each case is ignited to the corresponding oxide and weighed.     

Magnetic fluid based squeeze film between porous annular curved plates with the effect of rotational inertia

The squeeze film behaviour between rotating annular plates was analysed theoretically when the curved upper plate with a uniform porous facing approached the impermeable and flat lower plate, considering a magnetic fluid lubricant in the presence of an external magnetic field oblique to the plates. Expressions were obtained for pressure and load capacity; and response time is given by a differential equation. The increases in pressure and load capacity depended only on the magnetization. However, the increase in response time depended on magnetization, fluid inertia and speed of rotation of the plates.     

A mild and selective method for N-dealkylation of tertiary amines

Alkyl groups can be cleaved efficiently and selectively from tertiary alkyl amines using propargyl chloroformate. The propargyloxycarbonyl (Poc) protected secondary amines thus obtained can be deblocked under neutral and mild conditions using benzyltriethylammonium tetrathiomolybdate. The generality and compatibility of the method have been studied with a wide range of functionalities.     

Spectrophotometric studies of ruthenium(III)and rhodium(III)-oximidobenzotetronic acid complexes and the simultaneous determination of the two metals

Ruthenium(III) and rhodium(III) form stable coloured complexes in ethanolic solution with oximidobenzotetronic acid (OBTA). Ruthenium forms a purple-violet Ru(OBTA)(3) complex at pH 1.1-3.5, which is stable over the pH range 1.1-11.3. Rhodium(III) forms a yellowish-brown complex, RhCl(2)(OBTA)(2), at pH 2-8; at higher pH (11.5 and above) the complex is reddish-brown, but has the same Rh:OBTA ratio. A method for the simultaneous determination of these two metals is proposed, and the interference by commonly occurring ions has been investigated.     

High-performance liquid chromatographic determination of morphine, morphine-3-glucuronide, morphine-6-glucuronide and codeine in biological samples using multi-wavelength forward optical detection.

An isocratic high-performance liquid chromatographic method has been developed for the determination of morphine, morphine-3-glucuronide, morphine-6-glucuronide and codeine in plasma, urine and cerebrospinal fluid. The use of an efficient solid-phase extraction procedure together with a forward optical scanning detector allows a detection limit of 500 pg/ml. The method was evaluated by examination of biological samples taken from newborn infants following the intravenous administration of morphine sulfate.