Flow Injection Chemiluminescence Method for Nalbuphine Hydrochloride in Pharmaceutical Formulations Using Tris(2,2'-bipyridyl)ruthenium(II) Chloride-diperiodatocuprate(III) Reaction

Asensitive and selective method employing chemiluminescence(CL) coupled with flow injection(FI) is reported for nalbuphine hydrochloride(NAL) assay in pharmaceutical formulations. The enhancement effect of NAL on the CL reaction between tris(2,2'-bipyridyl)ruthenium(II) chloride-diperiodatocuprate(III) {Ru[(bpy)₃]²⁺-Cu(III) complex} in acidic medium is used as analytical measurement. The optimal conditions of the CL reaction were sulfuric acid 1.0×10^-3 mol/L, Ru[(bpy)₃]²⁺ 7.5×10^-5 mol/L, Cu(III)/Ag(III) complexes 4.0×10^-4/5.0×10^-4 mol/L, sample loop volume of 120 μL and flow rate of 2.5 mL/min. The sensitivities of the method in terms of detection(S/N=3) and quantification(S/N=10) limits are 5×10^-4 and 0.001 ppm(1 ppm=1 mg/L), respectively. The linear response of the instrument in the form of CL intensity with respect to NAL concentration is over the range 0.001-15.0 ppm(R²=0.9999) with relative standard deviation from 0.8% to 3.2% and injection throughput of 120 injection/h. The applications of the method include the quantitative analysis of NAL in pharmaceutical injection samples. Variations and the average results of the proposed method are not signi-ficantly different from the results of a reported method by applying F- and paired student t-test. The most likely CL reaction mechanism is written in accordance with spectrophotometric and CL studies.     

Chemiluminescence Determination of Cefixime Trihydrate Based on Acidic Diperiodatoargentate(Ⅲ)-Rhodamine 6-G System

A novel chemiluminescence(CL) method is proposed for cefixime trihydrate(CFX) determination based on its eiiliancement effect on diperiodatoargentate(III)(DPA)-rhodamine 6-G(Rh6-G) reaction in conjunction with flow injection analysis(FIA). A linear calibration curve was achieved over the range from 0.01 mg/L to 2.5 mg/L CFX(R^2=0.999,n=8) with relative standard deviation(RSD) of 1.4%-3.8%(n=4)), limit of detection(LOD) of 3.0×10^-3 mg/L(S/N=3),injection tliroughput of 180/h and regression equation of y=1113.2x-14.596[y=CL intensity (mV) and x=concentration of CFX(mg/L)]. The method was successfully applied to CFX determination in pharmaceutical formulations and the recoveries(%) for proposed FI-CL and a reported spectrophotometric method by applying the Student t-test [calculated t-test value: t=1.079215, and tabulated t-distributed(95%)=2.200985] were not significantly diflerent. The CFX was efficiently extracted and no significant effect of commonly found excipients in the pharmaceutical formulations was observed. The mechanism of CL reaction is discussed briefly.     

Double Series Identity and Some Laurent Type Hypergeometric Generating Relations

The main aim of this article is to obtain certain Laurent type hypergeometric generating relations. Using a general double series identity, Laurent type generating functions(in terms of Kampéde Fériet double hypergeometric function) are derived. Some known results obtained by the method of Lie groups and Lie algebras, are also modified here as special cases.     

MHD stagnation flow of a micropolar fluid through a porous medium

The unsteady MHD boundary layer flow of a micropolar fluid near the forward stagnation point of a two dimensional plane surface is investigated by using similarity transformations. The transformed nonlinear differential equations are solved by an analytic method, namely homotopy analysis method (HAM). The solution is valid for all values of time. The effect of MHD and porous medium, non dimensional velocity and the microrotation are presented graphically and discussed. The coefficient of skin friction is also presented graphically.     

Indefinite Least Squares Problem with Quadratic Constraint and Its Condition Numbers

In this paper,we consider the indefinite least squares problem with quadratic constraint and its condition numbers.The conditions under which the problem has the unique solution are first presented.Then,the normwise,mixed,and componentwise condition numbers for solution and residual of this problem are derived.Numerical example is also provided to illustrate these results.