NOPR Collection:

Catalyst selection for the lactonization of 1,4-butanediol

1996-07-01T00:00:00Z

Title: Catalyst selection for the lactonization of 1,4-butanediol Authors: Srinivas, B; Subrahmanyam, M; Kulkarni, S J; Rao, Y V Subba; Rao, A V Rama Abstract: Chromite catalysts have been studied with and with-out modifiers for lactonlzation of 1, 4 butanediol. The reaction on majority of the catalyst proceeds giving rise to cyclodehydration product, tetrahydrofuran (THF) mainly rather than cyclodehydrogenation product of y-butyrolactone (γ-BL). The lactonization of 1, 4-butanediol increases when the zinc chromite catalyst is modified with Pt metal. Few methods are discussed regarding the preparation and modification of the catalysts and their effects in selectivity from THF to γ-BL. Page(s): 237-238

Evaluation of stearyl-1-ά-naphthyl acetate as a stationary phase for gas-liquid chromatography

1996-07-01T00:00:00Z

Title: Evaluation of stearyl-1-ά-naphthyl acetate as a stationary phase for gas-liquid chromatography Authors: Husain, Sajid; Sarma, P Nageswara; Lakshmi, V V S; Rao, K Sita Rama Abstract: Stearyl-1-ά-naphthyl acetate has been prepared in the laboratory and evaluated as a stationary phase for gas-liquid chromatography after characterization by chromatographic and spectroscopic techniques. Several organic compounds, viz., aliphatic, aromatic and chlorinated hydrocarbons, cyclicethers, alcohols, ketones and esters have been used as test solutes. Classification of the stationary phase according to McReynolds' method, Novak's thermodynamic approach and Snyder's selectivity triangle has been carried out. The results reveal that the stationary phase falls in the medium polar category Industrially important compounds with close boiling points are satisfactorily resolved on this stationary phase. Investigations on the stability of the stationary phase showed that it is stable upto 140°C.It is concluded that stearyl-1-ά-naphthyl acetate can be used as a versatile, easily available and cheap stationary phase for GLC. Page(s): 234-236

Dissolution of Zn-Ni alloy deposited on foreign substrates

1996-07-01T00:00:00Z

Title: Dissolution of Zn-Ni alloy deposited on foreign substrates Authors: Ravindran, Visalakshi; Muralidharan, V S Abstract: Anodic linear sweep voltammetry (ALSV) has been used to identify the phase structure of alloy flims formed on foreign substrates. The studies on Zn-Ni alloy flims formed on glassy carbon and mild steel from sulphamate bath revealed the dissolution of a phase rich in zinc, along with a zinc phase from Zn-Ni alloy film. Page(s): 231-233

¹H-NMR Spectrometric determination of propranolol and its simultaneous determination in presence of xipamide in pharma ceutical preparations

1996-07-01T00:00:00Z

Title: ¹H-NMR Spectrometric determination of propranolol and its simultaneous determination in presence of xipamide in pharma ceutical preparations Authors: Husain, Sajid; Kifayatullah, M; Sekar, R Abstract: Fourier transform nuclear magnetic resonance (FTNMR) spectroscopic method for the determination of propranolol. HCI in pharmaceutical formulations is developed. A method for simultaneous determination of propranolol and xipamide is also described using tert-butyl alcohol as an internal standard. The proposed method is simple, rapid, selective and can be adopted in quality control laboratories. The results obtained by this method closely agree with those found by the method of British Pharmacopoeia (BP).No interference due to excipients is also observed. Page(s): 227-230

NOPR Collection:

Catalyst selection for the lactonization of 1,4-butanediol

Evaluation of stearyl-1-ά-naphthyl acetate as a stationary phase for gas-liquid chromatography

Dissolution of Zn-Ni alloy deposited on foreign substrates

1H-NMR Spectrometric determination of propranolol and its simultaneous determination in presence of xipamide in pharma ceutical preparations

¹H-NMR Spectrometric determination of propranolol and its simultaneous determination in presence of xipamide in pharma ceutical preparations