A simple, rapid and sensitive spectrophotometric method has been proposed for the determination of La (III) using 3-hydroxy -4-(2-hydroxy-phenyl azo) naphthalene -1- sulfonic acid as a chromogenic reagent. This method is based on the formation of a red-pink colored complex, upon the reaction of La(III) with the reagent in an alkaline medium (pH= 9.50), having a maximum absorbance at 459 nm. Beer's law is valid in the concentration range 0.512 µg.ml-1 with a Sandell's sensitivity value of 0.0188 µg.cm-2 and molar absorptivity of 7376.12 L.mol-1.cm-1. The stoichiometric composition of the chelate is 1:3. The effect of the presence of different cations as interferants in the determination of La(III) under the given optimum conditions

       Sildenafil, tadalafil, and vardenafil are phosphodiesterase type 5 enzyme (PDE-5) inhibitors used for the treatment of male erectile dysfunction. This present study aims to investigate 55 herbal products indicated for men’s sexual health from the Malaysian market for adulteration of PDE-5 inhibitors and analogues. The screening and identification of 20 PDE-5 inhibitors and analogues in herbal products of various forms (powder, capsules, tablets, and pastels) were conducted using gas chromatography–electron impact-mass spectrometer (GC-EI-MS). The analysis has shown that 19 herbal products were adulterated with PDE-5 inhibitors and analogues. Unique ion fragmentations and the presence of molecular

A rapid, simple and sensitive spectrophotometric method for the determination of trace amounts of chromium is studied. The method is based on the interaction of chromium with indigo carmine dye in acidic medium and the presence of oxalates as a catalyst for interaction, and after studying the absorption spectrum of the solution resulting observed decrease in the intensity of the absorption. As happened (Bleaching) for color dye, this palace and directly proportional to the chromium (VI) amount was measured intensity of the absorption versus solution was figurehead at a wavelength of 610 nm. A plot of absorbance with chromium (VI) concentration gives a straight line indicating that Beer’s law has been obeyed over the range of 0.5

A rapid, sensitive and selective spectrophotometric method was developed for determination of sulfathiazole (STHZ) in aqueous solution. The method is based on the  oxidative coupling reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH) in a basic medium (pH 10.9) in the presence of  potassium periodate to produce an intense orange colour, soluble in water , stable product and absorbs at 492 nm. Beer's law was in the linear range 2.0-28.0 μg/ml of sulfathiazole, the molar absorptivity, Sandellʼs sensitivity index and detection limit were 1.1437 ×104 liter. mol-1.cm-1,0.0223 μg.cm-2 and 0.1274 μg/ml respectively. The RSD value was  0.75 - 1.12 % depending on the concentration. This method was applied successfu

The synthesis and characterisation of new macrocyclic binuclear metal(II) complexes derived from dithiocarbamate (DTC) ligand are reported. The reaction of a bis-secondary amine, CS2 and KOH resulted in the formation of the free ligand. Two approaches were implemented to synthesis the macrocyclic bis(dithiocarbamate) complexes; (i) from the reaction of the free ligand with a metal ion, and (ii) via a one-pot reaction. In the free ligand approach, complexes were obtained by the reaction of dithiocarbamate salt with the metal ions; CoII, ZnII and CdII. However, the one-pot reaction is based on the mixing of the bissecondary amine, CS2, KOH and metal(II) chloride. Physico-chemical analyses were implemented to characterise the ligand and its

           A new ligand type (O₂) [2,3-O-diacetyl-5,6-O-benzylidene L- ascorbic acid] [L] and its complexes of general formula [M(L)₂(X)(Y)]Cl_n (where: M=Cr^III ,X=Y=H₂O, n=3; Co^II, X = Y = 0, n= 2; Ni^II and Cu^II, X = Cl, Y = H₂O, n= 1; Zn^II, X = Y = H₂O,n = 2) are reported. The ligand was prepared in two steps; first step involved the synthesis of [5,6-O-benzylidene-L-ascorbic acid] (A). In second step derivative-A was then reacted with acetyl chloride and anhydrous pyridine as a base to give the titled ligand. Metal complexes of the ligand with Cr^III,Co^II

A series of new Bis-1,4-Butane -1,3,4 – Oxadizole derivatives [III a-j] were synthesized from adipic acid dihydrazide and different aromatic acids in the presence of phosphours oxychloide. There compounds were characterized by their IR, microanalysis, and mass spectral data.    In vitro antimicrobial were synthesized. In vitro antimicrobial activity of these compounds against (Gram negative) and (Gram positive) were reported, some of these compounds prepared derivatives exhibited antimicrobial activity

A simple, accurate and sensitive spectrophotometric method for the determinaion of epinephrine is described . The method is based on the coordination of Pr (III) with epinephrine at pH 6. Absorbance of the resulting orange yellow complex is measured at 482 nm . A graph of absorbance versus concentrations shows that beer 's low is obeyed over the concentration range (1-50)mg.ml-1 of epinephrine with molar absorpitivity of ( 2.180x103 L.mol-1.cm-1 ), a sandell sensitivity of (0.084 mg.cm-2 ), a relative error of (-2.83%) , a corrolation coffecient (r= 0.9989) and recovery % ( 97.03 ± 0.75 ) depending on the concentration.This method is applied to analyse EP in several commercially available pharmaceutical preparations