http://nopr.niscpr.res.in/handle/123456789/17945 Fri, 09 Oct 2026 03:21:27 GMT 2026-10-09T03:21:27Z http://nopr.niscpr.res.in/handle/123456789/17978 Title: Spectrophotometric determination of hydroxylamine and its derivatives in drug formulations by the indophenol reaction Authors: Deepa, B; Nagaraja, K S; Balasubramanian, N Abstract: Hydroxylamine has been determined by its reduction to ammonium sulphate in Zn/H₂SO₄ column and Berthelot reaction of the formed ammonium sulphate using salicylic acid, sodium hypochlorite and sodium nitroprusside to give indophenol blue which is measured spectrophotometrically at 648 nm. The molar absorptivity is found to be 1.9×10⁴ 1 mol^-1cm^-1. Beer's law is obeyed in the range 2.5 - 25 μg of hydroxylamine in 10 ml of its solution. For the <span style="font-size:14.0pt;line-height:115%;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";color:black;mso-ansi-language:en-in;="" mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">determination of 1.5 μg/ml of hydroxylamine, the RSD is 2.8% (n=10). The developed method has been applied for the determination of hydroxylamine and its derivatives after hydrolysis in drug formulations. The results obtained by the present method compare well with those obtained by the available reference method and with the standard addition of hydroxylamine.</span> Page(s): 913-916 Sat, 01 Apr 2006 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/17978 2006-04-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/17977 Title: Catechol (l ,2-dihydroxybenzene) inside charged film on electrode surface— A new voltammetric sensor for vitamin C Authors: Bhattacharjya, Rimki; Das, Diganta Kumar Abstract: Catechol shows good reversible cyclic voltammograms inside negative SDS, positive CTAB and zwitterionic phospholipid film on glassy carbon disc electrode in tris buffer (<i>p</i>H 7.0). The mid point potential values with respect to Ag-AgCl reference electrode are found to be +120 mV, +90 mV and +135 mV, respectively. While inside the SDS film, catechol interacts with vitamin C in solution and the anodic current decreases with increasing concentration of vitamin C without any change in cathodic peak current and position. Although no interaction with vitamin C is observed when catechol is inside CTAB film, the mid-point potential of Catechol inside lipid film is round to shift in negative direction when encapsulated in lipid film. Page(s): 909-912 Sat, 01 Apr 2006 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/17977 2006-04-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/17976 Title: A study on interaction between benzyl alcohol and cationic surfactant micelles by ¹H NMR Authors: Wei, Xi-Lian; Yin, Bao-Lin; Cui, Ji-Chun; Liu, Jie; Sun, De-Zhi Abstract: Solubilization of benzyl alcohol in aqueous micellar solution of 3-alkoxy-2-hydroxypropyl trimethyl ammonium bromides (C_nH_2n+1OCH₂CH(OH)CH₂N(CH₃)₃⁺ Br^-, abbreviated as C_nNBr, (<i>n</i>=8, 12, 14, 16) has been studied by high resolution ¹H NMR. Results indicate that the alkyl chain length of the surfactant affects the solubility of benzyl alcohol in the micellar solution. The peak of methylenes in long chain surfactant splits into an upfield signal and a down field signal when the solubilization system is at high molar ratio of benzyl alcohol to surfactant. The solubility of benzyl alcohol in micelle solutions of different surfactants (<i>n</i>=8, 12, 14 and 16)at the same concentration (3.00×10^-2mol L^-1) are 0.1125, 0.1470, 0.1755 and 0.2100 mol L^-1, respectively. The transfer free energy of benzyl alcohol from aqueous phase to micellar phase is – 18.45, - 18.59, - 18.72 and - 18.80 kJ mol^-1 for <i>n</i> = 8, 12, 14 and 16, respectively. Page(s): 905-908 Sat, 01 Apr 2006 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/17976 2006-04-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/17975 Title: Kinetics and reactivity of indole-2,3 –dione ring towards alkali in dimethyl sulphoxide-water mixtures Authors: Fathalla, Magda F; Ismail, Amel M Abstract: Kinetics of alkaline hydrolysis of indole-2,3 -dione (isatin) and indole-2,3-dione (N- melhyl isatin) have been carried out at different percentages of DMSO-H₂O mixtures and at different temperatures in the range 30-45°C. The reaction proceeds according to pesudo first-order kinetics. The presence of an electron releasing substituent melhyl group attached to nitrogen atom accelerates the reaction rate. Thermodynamic activation parameters ΔH^#, ΔS^#<i> </i>and ΔG^# have been determined. The negative values of entropy of activation and the non- linear relation between log rate constant and reciprocal of dielectric constant suggest selective solvation by the higher polar water solvent molecules. Page(s): 901-904 Sat, 01 Apr 2006 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/17975 2006-04-01T00:00:00Z