NOPR Community:

Determination of ketoximes in low molecular and polymeric systems by acetic anhydride method

Sun, 01 Nov 1998 00:00:00 GMT

Title: Determination of ketoximes in low molecular and polymeric systems by acetic anhydride method Authors: Mathew, G D Gem; Pillai, V N Rajasekharan Abstract: Analytical procedure for the estimation of ketoximes in low molecular and polymeric systems based on acetylation has been described. The method has been found to be very simple, cost-effective and reliable for a number of ketoximes. Page(s): 407-408

Synthesis of acetonitrile by dehydration of acetamide on an active ZnO catalyst: A comparison with zeolite catalysts

Sun, 01 Nov 1998 00:00:00 GMT

Title: Synthesis of acetonitrile by dehydration of acetamide on an active ZnO catalyst: A comparison with zeolite catalysts Authors: Naik, Sajo P; Fernandes, Julio B Abstract: A catalytic activity of three different zinc oxides is evaluated in dehydration of acetamide reaction at 723 K. It is seen that an oxide of zinc, ZnO(u) prepared by decomposition of a mixture of zinc nitrate, urea and oxalic acid method showed much higher activity than other zinc oxides. Also the activity of ZnO(u) was comparable with the reported activities of zeolite catalysts. The activity of the catalysts could be correlated with their acidity. Page(s): 405-406

Detection of nitric oxide using an optical sensor

Sun, 01 Nov 1998 00:00:00 GMT

Title: Detection of nitric oxide using an optical sensor Authors: Pandey, P C Abstract: An optical sensor for nitric oxide (NO) is described. The sensor involves a flow injection analysis (FIA) system coupled with an evanescent wave (EW) sensor employing total internal reflection of fluorescence radiation (TIRF). The detection is based on the measurement of the decrease in fluorescence response in the presence of NO of a highly fluorescent product which is the complex of glutathione and 7-diethylamino-3-(4'-maleimidylphenyl)-4methylcoumarin (CPM). CPM forms a highly fluorescent product with thiol containing compound i.e. cysteine/glutathione which can be detected using an evanescent fluorosensor. NO form a stable complex with glutathione/cysteine which then does not react with CPM to form fluorescent product. Thus there is a decrease in the fluorescence signal on increasing concentration of NO with constant concentration of glutathione. An excellent FIA response has been observed on the injection of the constant concentration of CPM-glutathione product obtained by treating constant concentration of glutathione with varying concentration of NO. The lowest detection limit of NO is found to the order of 0.10 µM. Page(s): 402-404

Comparison of catalytic activity of immobilized amyloglucosidase on DEAE-cellulose with native enzyme on dextrin-hydrolysis

Sun, 01 Nov 1998 00:00:00 GMT

Title: Comparison of catalytic activity of immobilized amyloglucosidase on DEAE-cellulose with native enzyme on dextrin-hydrolysis Authors: Rani, AS; Das, M L M; Rao, A Rajeshwar; Satyanarayana, S Abstract: Amyloglucosidaseis an exo-enzyme which is used in the saccharification of starch in industries. In this study the catalytic activity of amyloglucosidase immobilized on DEAE-cellulose (diethyl amino ethylcellulose) was investigated and compared with native enzyme on hydrolysis of dextrin. Amyloglucosidase was immobilized on DEAE-cellulose by ionic binding method. Activity of DEAE-cellulose immobilized and native enzymes were compared and it was observed that mobilized amyloglucosidase has 78% of the catalytic activity of native enzyme. The activity of DEAE-cellulose immobilized enzyme as a function of pH and temperature was determined. Kineti cconstants K_m and V_max were also determined. Page(s): 397-401