生物分析および生物医学ジャーナル

In this paper we have used a modified homotopy perturbation method used previously by A. Belendez and his coworkers, for calculation of axial secular frequencies of a nonlinear ion trap with hexapole, octopole and decapole superpositions. We transform the motion of the ion in a rapidly oscillating field to the motion in an effective potential and obtain a nonlinear differential equation in the form of a Duffing-like equation. With only octopole superposition the resulted nonlinear equations are symmetric; however, in the presence of hexapole and decapole superpositions, they are asymmetric. For asymmetric oscillators, it has been pointed out that the angular frequency for positive amplitudes is different from the angular frequency for negative amplitudes. Considering this problem, the modified homotopy perturbation method is used for solving the resulted nonlinear equations. As a result, the ion axial secular frequencies as a function of nonlinear field parameters are obtained. The calculated secular frequencies are compared with the results of modified Lindstedt-Poincare approximation and the exact results. There is an excellent agreement between the results of this paper and the exact results.

Palm oil has been part of human diet for more than 5000 years. For generations, it has been revered as both a nutritious food and a valuable medicine. However, care should be taken to evaluate the purity and safety of this nutritional and medicinal agent to the human system. This study investigated the concentration of cadmium, chromium, mercury, lead, arsenic and nickel in twenty-five samples of ready-to consume palm oil that were bought randomly from different markets in Lagos, Nigeria. The samples were digested with aqua-regia (2:1:2 HNO3:HClO4:H2SO4 respectively) and the digested samples were analyzed using Atomic Absorption Spectroscopy. There was no detectable mercury in one of the twenty-five samples analysed. However, all the samples contained a detectable amount of each of the other five metals analysed. The Oral Component Limit (OCL) for cadmium, chromium, mercury, lead, arsenic and nickel as stated by USP are 0.5μg/g, 25 μg/g, 1.5 μg/g, 1 μg/g, 1.5 μg/g and 25 μg/g respectively. The samples contained detectable amounts of the metals although with values below the USP standard OCL. The results obtained from this study suggest that the palm oil samples analysed are save for consumption in terms of the metals of interest analysed.

Accurate, simple, sensitive, reproducible and specific liquid chromatographic method has been developed for
estimation of BITS-17 in rat plasma and other biological tissues using β-naphthol as an internal standard (IS). The applicability of the validated method was tested to estimate the concentrations of BITS-17 (a novel anti tubercular agent) in plasma and tissues that were harvested in a rat tissue distribution study. A liquid - liquid extraction technique was used to extract BITS-17 and internal standard from the plasma and various tissue homogenates. The main pharmacokinetic parameters obtained after intravenous administration were t½=14 ± 0.20 h, Kel=0.62 ± 0.10 h-1, mean plasma clearance=1.35 ± 0.16 mg/h and mean volume of distribution = 1.99 ± 0.49L. The systemic absorption was tested with two formulations was slow after oral administration and maximum bioavailability was 33.02%. The peak plasma concentration of both the formulations was found to be 1.31 ± 0.06 and 1.0 ± 0.12 mg/mL, respectively, which was much above the levels of minimum inhibitory concentrations of BITS-17. The concentrations of BITS-17 were found in various tissues but the levels in lung and brain signifies a good therapeutic target.