Three inherent acidic chitinases were purified from yam aerial tuber by the application of quaternary ammonium ion detergent. For remoyal of the mucilage in the crude extract of aerial tuber, the effeets of various quaternary ammonium ion detergent were compared. Cetylpyridinium chloride effectiyely remoyed the mucilage and this method proyed to provide high recoyery of chitinase actiyity. Thre...

The superposition model has been used to investigate the substitution of Mn in ammonium oxalate monohydrate. The zero field splitting parameters D and E calculated by the superposition model are compared with the experimental values Dexp and Eexp, respectively, for Mn obtained by electron paramagnetic resonance. Both the zero field splitting parameters D and E calculated theoretically are in go...

The ammonium counter ion is shown to influence the morphology, physicochemical properties and electrochemical performance of hydrothermal carbon.

Campbell, J. N. (American Meat Institute Foundation, Chicago, Ill.), James B. Evans, Jerome J. Perry, and C. F. Niven, Jr. Effect of ammonium ion on growth and metabolism of Micrococcus sodonensis. J. Bacteriol. 82:823-827. 1961.-When Micrococcus sodonensis was grown in a synthetic medium deficient in ammonia, large quantities of alpha-keto acids, chiefly alpha-ketoglutaric, accumulated in the ...

background: surface water and groundwater pollution with various forms of nitrogen such as ammonium and nitrate ions is one of the main environmental risks. the major objectives of this study were to evaluate the capacity of natural zeolite (clinoptilolite) to remove no3- and nh4+ from polluted water under both batch and column conditions. methods: the laboratory batch and column experiments we...

Ion pair dispersive liquid- liquid microextraction (IP-DLLME) method combined with flame atomic absorption spectrometry was proposed for the determination of trace amounts of copper(II). By using pyrocatechol violet as chelating agent and cetyltrimethyl ammonium bromide as an ion pairing agent, the trace amount of copper(II) was extracted in chloroform. The factors influencing the formation cop...

novel collagen-based hydrogel nanocomposites were synthesized by graft copolymerization of acrylamide and maleic anhydrid in the presence of different amounts of montmorillonite, using methylenebisacrylamide (mba)and ammonium persulfate (aps) as crosslinker and initiator, respectively. the optimum amount of clay on the swelling properties of the samples was studied. it was found that the hydrog...

A mixed-mode solid-phase extraction procedure was developed for the isolation and purification of acidic compounds from complex biological matrices. Urine samples were spiked with several acidic drugs and diluted in ammonium acetate buffer. Isolute HAX columns (a mixed-mode phase consisting of both hydrophobic and ion-exchange ligands) were conditioned with methanol and ammonium acetate prior t...

The kinetic data obtained for the cycloadditions of the permanganate ion to a series of styrene derivatives in dichloromethane solution in the presence of a quaternary ammonium ion were examined with two theoretical approaches, on the assumption that the reactions proceed via a concerted [3 + 2] mechanism. The semi-quantitative frontier molecular orbital analysis of the kinetic data shows a lin...

RATIONALE Because of the threat of bombings using improvised explosives containing ammonium nitrate (AN), law enforcement and intelligence communities have been interested in stable isotope techniques for tracking and discriminating AN sources. Separate analysis of the AN component ions ammonium and nitrate would add discriminatory power to these techniques. METHODS Ammonium ions in dissolved...