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51.
Gopalakrishna A. Suryanarayana S. V. Naik H. Nayak B. K. Patil B. J. Devraju S. Upreti R. R. Kinhikar R. Deshpande D. D. Maletha P. Kamaldeep Banerjee S. Saxena A. 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(3):1409-1417
Journal of Radioanalytical and Nuclear Chemistry - The medical isotopes 99Mo and 64Cu were produced via the dual routes of 100Mo(γ,n)99Mo + 98Mo(n,γ)99Mo and 65Cu(γ,n)... 相似文献
52.
A. Peter Snyder Shirley A. Liebman Suryanarayana Bulusu Michael A. Schroeder Robert A. Fifer 《Journal of mass spectrometry : JMS》1991,26(12):1109-1118
Analytical pyrolysis-atmospberic pressure ionization (Py-API) tandem mass Spectrometry was used in the structure elucidation of the oxidalive and non-oxidative thermal decomposition products of cyclotetramethylenetetranitramine (HMX). The [15NO2]-, [15N8]- and [2H8]-HMX isotope preparations provided fundamental information in the determination of the identities of the various pyrolyzate species. All RDX pyrolysis product ions that were identified by Py-API tandem mass Spectrometry, i.e. m/z 44, 60, 74, 75, 85 and 98, were present in the pyrolyzate of HMX. In both RDX and HMX investigations, these ions provided identical mass spectral daughter ion analyses. HMX, however, provided additional ions at m/z 30, 58, 69, 71, 83 and 141. Of all thirteen ions identified in the Py-APJ mass spectrum of HMX, only that at m/z 75 contained a nitrogen atom that originated from the NO2 group. Standards analysis confirmed the identities of the ions at m/z 69, 71 and 141 as methyleneaminoacetonitrile, methylaminoacetonitrile and the caged compound hoxamethylenetetraamine, respectively. Isotopic analyses provided a high degree of confidence on the structural assignments of the ions at m/z 30 and 58 as methyleneimine and methyleneformamide; the ion at m/z 83, however, appeared to be a heterocyclic compound with daughter ion mass spectral elements similar to but not identical with that of 1-methylimidazole and 3-methylpyrazole. 相似文献
53.
Summary A new volumetric method has been developed for the determination of molybdenum(VI). The method consists in the reduction of molybdenum(VI) by heating with a slight excess of hydrazine sulphate in 1 to 2 M hydrochloric acid medium for ten minutes on a water bath. The mixture is cooled and the molybdenum(V) obtained determined by titration with a standard solution of ceric sulphate at an overall acidity of 4 N hydrochloric acid, using diphenyl benzidine as indicator and adding 5 ml of syrupy phosphoric acid for 50 ml of the mixture. Alternately the molybdenum(V) can be titrated with a standard solution of ceric sulphate at an overall acidity of 3 N hydrochloric acid using ferroin as indicator and adding 5 ml of syrupy phosphoric acid for 50 ml of the titration mixture. The molybdenum(V) can also be titrated with a standard solution of sodium vanadate in 8 N sulphuric acid medium, using N-phenyl anthranilic acid as indicator. Alternately, the titration with sodium vanadate can be made with diphenyl benzidine as indicator in 4 N acid medium, adding 5 ml of syrupy phosphoric acid and 1 ml of 1.0 M oxalic acid to catalyse the indicator action. The method now proposed is much more convenient than the methods currently available. It is simple because it does not require any costly chemicals or complicated apparatus. Furthermore, it has the advantages of great rapidity and excellent precision. 相似文献
54.
G. Saravanan B. M. Rao M. Ravikumar M. V. Suryanarayana N. Someswararao P. V. R. Acharyulu 《Chromatographia》2007,66(3-4):287-290
Chromatographic separation of lenalidomide and its impurities was achieved on an Inertsil ODS-3 V column using a mobile phase
consisting of a mixture of buffer, acetonitrile and methanol in the ratio 80:8:12 v/v. Degradation studies were performed on bulk samples of lenalidomide subjected to 0.5 N hydrochloric acid, 0.5 N sodium hydroxide,
10% v/v hydrogen peroxide, heating to 60 °C and UV light at 254 nm. Degradation was observed only under base hydrolysis conditions.
The developed LC method gave a mass balance close to 99.5%, proving it to be suitable for stability studies and was validated
with respect to linearity, accuracy, precision and robustness. 相似文献
55.
Vydyula Pavan Kumar Perepogu Arun Kumar Iragavarapu Suryanarayana Yadavalli Venkata Durga Nageswar Kakulapati Rama Rao 《Helvetica chimica acta》2007,90(9):1697-1704
The two pyrrolidinylidenesulfamido‐modified β‐cyclodextrins (β‐CDs) 3 and 4 were prepared and studied for chiral discrimination of the enantiomers (R)‐ and (S)‐ 1 of zolmitriptan. The pyrrolidinylidenesulfamido spacer improved the chiral discrimination and binding abilities of these modified cyclodextrins. The hosts 3 and 4 showed higher selectivity for (S)‐ 1 . The association constants (Table) and enantioselectivity factors were calculated for the complexes of (R)‐ and (S)‐ 1 with the β‐CDs 2 – 4 . The formation of host?guest complexes was confirmed by 1H‐NMR studies. 相似文献
56.
L. Manral P. K. Gupta M. V. S. Suryanarayana K. Ganesan R. C. Malhotra 《Journal of Thermal Analysis and Calorimetry》2009,96(2):531-534
Flash pyrolysis of fentanyl and its analogues has been studied on pyrolysis-gas chromatograph-mass spectrometer (Py-GC-MS)
system. Initial pyrolytic fragmentation of these compounds led to the formation of N-substituted-1,2,5,6-tetrahydropyridine
and N-phenylpropanamide as the primary pyrolytic products. Moreover, depending up on the furnace temperature, these pyrolytic
products can also undergo further fragmentation to give different compounds. We, herein, discuss the probable fragmentation
routes of parent as well as pyrolytic products. This study will be useful while developing technologies for thermal aerosol
generation of fentanyl and related compounds. 相似文献
57.
58.
M. V. R. Prasad D. S. Suryanarayana R. K. Jeevanram 《Journal of Radioanalytical and Nuclear Chemistry》1994,178(2):399-406
A simple carrier-free method has been developed for estimating 0.1 to 1.1 Bq of106Ru in urine. The organic matter present in urine samples was completely destroyed by wet ashing using nitric acid-peroxide mixture in presence of sulfuric acid. Ruthenium was oxidized to tetroxide using potassium periodate and allowed to react in-situ with polyethylene powder. The powder was separated, washed, pelletized and its -activity was counted. Recovery of106Ru is found to be better than 80% with a minimum detection limit of 0.2 Bq/dm3 which is less than the DRL value specified by International Commission on Radiological Protection (ICRP). 相似文献
59.
Lakshmi Niranjan Reddy V Ravinder K Srinivasulu M Venkateshwar Goud T Malla Reddy S Srujankumar D Prabhakar Rao T Suryanarayana Murty U Venkateswarlu Y 《Chemical & pharmaceutical bulletin》2003,51(9):1081-1084
The stems of Boswellia ovalifoliolata BAL. & HENRY (Burseraceae) afforded two new macrocyclic diaryl ether heptanoids, ovalifoliolatin A (1) and B (2) together with three known compounds; acerogenin C (3), 3 alpha-hydroxyurs-12-ene (4), and sitost-4-en-3-one (5). The structures were established by means of spectroscopic analysis and compounds 1, 3-5 were evaluated for their antibacterial activity. 相似文献
60.
A. Suryanarayana N. Kürmaiah G. Somidewamma V. Pandu Ranga Rao 《Fresenius' Journal of Analytical Chemistry》1964,202(6):422-425
Summary Suitability of vanadium(V), manganese(VII), cerium(IV) and chromium(VI), as oxidants in the titration of iron(II) in the presence of EDTA has been investigated and vanadium(V) has been found to be the best one for that purpose, as titration with this reagent is not influenced by any interference. Cerium(IV) can be used provided phosphoric acid or bismuth nitrate is added to eliminate the interference by EDTA. Chromium(VI) is useful only in the presence of bismuth salt. This effect of bismuth nitrate is not observed in hydrochloric acid medium. Manganese(VII) cannot be used even in the presence of bismuth nitrate, since manganese(II) catalyses the reaction between manganese(VII) and even the metal bound EDTA. Optimum conditions for the quantitative photochemical reduction of iron(III) by EDTA are established.
Zusammenfassung Die Eignung von VV,MnVII,CeIV und CrVI zur Titration von Eisen(II) in Gegenwart von ÄDTA ist untersucht worden. VV hat sich am besten bewährt und ist keinen Störungen ausgesetzt. CeIV kann bei Zusatz von Phosphorsäure oder Wismutnitrat benutzt werden. CrVI nur bei Gegenwart von Wismutsalz. Die Wirkung von Wismutnitrat konnte in salzsaurem Medium nicht beobachtet werden. MnVII kann auch bei Gegenwart von Wismutsalz nicht verwendet werden, da MnII sogar die Reaktion zwischen MnVII und dem metallgebundenen ÄDTA katalysiert. Die optimalen Bedingungen für die quantitative photochemische Reduktion von Eisen(III) mit ÄDTA wurden ausgearbeitet.相似文献