Direct FIA methods for estimation of Naringenin (NG) in different samples were proposed. These methods are based on diazotization coupling reactions of two reagents: method (A) p-chloroaniline (PCA) and method (B) procaine hydrochloride (PRH) with NG in basic medium. Yellow dyes with maximum absorption at 416 and 415 nm were formed respectively. Calibration curves were constructed over different NG concentrations, linearity was from 1- 70 and 1- 40 µgmL^-1 with detection limits of 0.55 and 0.24 µgmL^-1 for (A) and (B) respectively. All analytical variables involved in the FIA procedure were evaluated and optimized. The established methods were successfully applied for the determination of NG in its supplements and u

A simple and rapid high performance liquid chromatographic with fluorescence detection method for the determination of the aflatoxin B1, B2, G1 and G2 in peanuts, rice and chilli was developed. The sample was extracted using acetonitrile:water (90:10, v/v%) and then purified by using ISOLUTE multimode solid phase extraction. After the pre-column derivatisation, the analytes were separated within 3.7 min using Chromolith performance RP-18e (100–4.6 mm) monolithic column. To assess the possible effects of endogenous components in the food items, matrix-matched calibration was used for the quantification and validation. The recoveries of aflatoxins that were spiked into food samples were 86.38–104.5% and RSDs were <4.4%. The method was

Simple and sensitive batch and flow injection methods (normal and reverse flow injection analysis (nFIA and rFIA)) for spectrophotometric determination of vancomycin hydrochloride (VHC) in pharmaceutical preparations were proposed and optimized. Both methods are based on the oxidative - coupling reaction between vancomycin hydrochloride and 2,4-Dinitrophenylhydrazine (DNPH) in the presence of sodium periodate in alkaline medium to form a yellow water-soluble product that is stable and has a maximum absorption at 461 nm. Beer’s law was obeyed over the range of 1- 40, 0.5-120 and 0.5-150 μg.mL-1; the limits of detection were 0.537, 0.0823 and 0.233 μg.mL-1 for batch, normal and reverse flow injection methods respectively. The sampling

    The weak and strong forms are so called because it is not their lexical content that primary matter, but the role they have in the sentence. The problematic confusion, our students encounter, in recognizing and producing the correct pronunciation of weak and strong forms of the English function words is the main incentive behind conducting  this study. In order to gather the data, this paper used two types of tests: a recognition test and a production test. The general results reached  through the analysis of the students' answers seem to conform to the researcher's assumption: students face a critical problem in recognizing and producing correct pronunciation of the weak and strong forms of the English funct

The purpose of this paper is to introduce a new type of compact spaces, namely semi-p-compact spaces which are stronger than compact spaces; we give properties and characterizations of semi-p-compact spaces.

Csaszar introduced the concept of generalized topological space and a new open set in a generalized topological space called -preopen in 2002 and 2005, respectively. Definitions of -preinterior and -preclosuer were given. Successively, several studies have appeared to give many generalizations for an open set. The object of our paper is to give a new type of generalization of an open set in a generalized topological space called -semi-p-open set. We present the definition of this set with its equivalent. We give definitions of -semi-p-interior and -semi-p-closure of a set and discuss their properties. Also the properties of -preinterior and -preclosuer are discussed. In addition, we give a new type of continuous function

  The aim of this paper is to introduce a new type of proper mappings called semi-p-proper mapping by using semi-p-open sets, which is weaker than the proper mapping. Some properties and characterizations of this type of mappings are given.

Based on the density functional theory (DFT) , the stability of molecular complexes has been predicted according to hard-soft acid base (HSAB) theory. Relative stability of products and reactivity of soft base sulfide derivatives with halogens (Iodine , Bromine , Chlorine) as soft acid was studied to determine the relative ability of these reactants causing the reaction to be more spontaneous.
DFT at the levels of B3LYP/3-21G and B3LYP/3-21G (d) was used to study HOMO LUMO energy gaps , bonds length and total energy to calculate the softness sequence of each type of acid or base mentioned in this work. All cases studied prove that iodine can be considered as the most softness acid and ethyl methyl sulfide≈ dimethyl sulfide the most