Phenol-Hypochlorite Reaction for Determination of Ammonia

Analytical Chemistry (Impact Factor: 5.64). 07/1967; 39(8). DOI: 10.1021/ac60252a045
333 Reads
  • Source
    • "The remainder of the water extract was filtered through Whatman 54 filter paper (Whatman Inc., Clifton, NJ), acidified with 50% H 2 SO 4 , and analyzed for ammonia, water soluble carbohydrates (WSC), organic acids, 1,2-propanediol, and ethanol. Ammonia was measured using the colorimetric phenol-hypochlorite method (Weatherburn, 1967). The WSC were quantified by a colorimetric procedure (Nelson, 1944). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Ethanol and other volatile organic compounds (VOC) are formed during ensiling, and may contribute to poor air quality and reduce feed intake by animals. Chemical or biological additives may help address these problems by reducing production of VOC during ensiling. The purpose of this study was to evaluate the effect of additives on production of nine silage VOC in corn silage, including compounds thought to contribute to poor air quality or affect feed intake (alcohols: methanol, ethanol, 1-propanol; esters: methyl acetate, ethyl acetate, ethyl lactate; and aldehydes: acetaldehyde, valeraldehyde, hexanal). Potassium sorbate, an anti-fungal additive that has shown promising results in reducing ethanol and ester concentrations (1 g/kg on a fresh mass basis); a facultative heterofermentative lactic acid bacterium, Lactobacillus plantarum MTD1 (105 cfu/g on a fresh mass basis); and a combination of both additives were compared to a control treatment, which received only water. Silage was made in bucket silos which were opened after 119 days of ensiling. Potassium sorbate reduced ethanol production by >70% and ethyl lactate and ethyl acetate by >65% whether or not L. plantarum was included. Other compounds were not clearly affected by either additive when used individually, but the combined treatment reduced 1-propanol and valeraldehyde. The concentration of valeraldehyde was increased by L. plantarum. Neither potassium sorbate treatment increased concentrations of any measured VOC. These results provide additional evidence that potassium sorbate is an effective additive for reducing production of ethanol and ethyl esters in corn silage. Combining potassium sorbate with L. plantarum may provide additional benefits, although the persistence of this effect for silages with higher VOC concentrations needs to be evaluated.
    Animal Feed Science and Technology 10/2015; 208:79-85. DOI:10.1016/j.anifeedsci.2015.07.007 · 2.00 Impact Factor
  • Source
    • "Condensed tannins (CT) were measured using 2% ferric ammonium sulfate in 2N HCl and butanol-HCl (95:5, v/v). For in vitro and in vivo rumen fluid measurements, ammonia nitrogen (NH 3 -N) was determined using the indophenol reaction (Weatherburn, 1967). The volatile fatty acid (VFA) concentrations in rumen fluid were measured using gas chromatography (GC- 12A; Shimadzu Co., Japan,) with a FAL-M column (Shimadzu Co., Japan). "

  • Source
    • "plays an important role in the virulence of some bacterial pathogens as well as determinant in pathogenesis of many diseases in human. It is involved in the production of infectious stones; add to the pathogenesis of urolithiasis, pyelonephritis, and hepatic encephalopathy (Weatherburn, 1967). The urease results in pathologies by "
    [Show abstract] [Hide abstract]
    ABSTRACT: In the continuation of our work to synthesize enzyme inhibitors. We synthesized 3,4,5-trihydroxybenzohydrazones (1-19) from 3,4,5-trihydroxybenzohydrazide, which were obtained from methyl 3,4,5-trihydroxybenzoate by refluxing with hydrazine hydrate. All the synthesized compounds were characterized by different spectroscopic methods. The synthesized compounds were evaluated for urease inhibition and showed excellent results, closed to the standards thiourea. The kinetics studies on the five most active compounds 6, 10, 14, 16 and 18 were carried out to determine their mode of inhibition and dissociation constant Ki. The compounds 6 and 16 were found to be competitive inhibitors with Ki values 19.1 and 10.53 μM, respectively, while the compounds 10, 14 and 18 were found to be mixed-type of inhibitors with Ki values in the range of 18.4- 21.7 μM.
    Arabian Journal of Chemistry 07/2015; 23. DOI:10.1016/j.arabjc.2015.06.036 · 3.73 Impact Factor
Show more