USP guidelines were used to determine the suitability of system which consists of optimized conditions, i.e., merging of ammonium acetate buffer solution pH 7.6 and acetonitrile
50:50% v/v as mobile phase at a flow rate of 0.5 mL/min over Agela C18, 125 mm x 4.6 mm, 5 um.
Raw chitosan was allowed to swell in the acetonitrile
solvent at room temperature, and then (CH3)3CO-K+ dissolved in acetonitrile
was added, and stirred for 24 h.
The electronic absorption spectra of pyrazoloisoindol derivative ligand and its [Ag.sup.+], [Co.sup.2+], [Hg.sup.2+], [Zn.sup.2+], [Ni.sup.2+], [Cu.sup.2+], [Cd.sup.2+], [Mn.sup.2+], [Cr.sup.3+], [Fe.sup.3+] and [Pb.sup.2+] complexes in acetonitrile
are shown in Figure 2.
Silicon wafers (SUMCO Corporation, Japan), methanol (99.7%, Sigma-Aldrich, USA), ethanol (95%, Sigma-Aldrich, USA), acetonitrile
(99.8%, Sigma-Aldrich, USA), chloroform (E-Merck, Germany), carbon tetrachloride (Qualikems, India), isopropanol (Panreac Quimica Co., Spain), benzene (E-Merck, Germany), dioxane (Fisher Scientific Co., UK), hexane (99.9%, Avonchem, UK), hydrofluoric acid (THF, Panreac Quimica Co., Spain), tetrahydrofuran (THF) (Nexgen Chemicals, India), hydrogen peroxide ([H.sub.2][O.sub.2]) (Avonchem, UK), dimethyl sulphoxide (DMSO) (99% Fluka Chemika, USA), dimethylformamide (DMF) (99.8%, Panreac Quimica Co., Spain), chloroplatinic solution, and distilled water (DI) were of analytical grade and used directly as received without any further purification.