Ammonium Hydroxide Reagent

B. Ammonium Hydroxide Reagent. Colver (Ref 1) and Marshall(Ref 5) tabulated colors produced by alcoholic ammonia, but did not describe the prepn of the reagent. The reagent prepd by mixing equal vols of Amm hydroxide and alcohol was used during WWH at Keystone OdnWorks for testing expls... 

Formaldehyde Methyl iodide Trimethyl phenyl ammonium hydroxide reagent, milk testing Acid blue 74 FD C Blue No. 2 reagent, modified Karl Fischer Methoxyethanol reagent, molybdenum Basic violet 10... 

Van den Berg JDJ and Boon JJ (2001) Unwanted alkylation during direct methylation of fatty (di)acids using tetra-methyl ammonium hydroxide reagent in a Curie-point pyrolysis unit. Journal of Analytical and Applied Pyrolysis 61 45-63. 

Add 1.5-2.5 mL of 30% ammonium hydroxide (reagent grade), close the screw cap tightly, and incubate using heat block or water bath for at least 5 h or longer for G-rich sequences at 55°C. 

Freshly opened bottles of these reagents are generally of the concentrations indicated in the table. This may not be true of bottles long opened and this is especially true of ammonium hydroxide, which rapidly loses its strength. In preparing volumetric solutions, it is well to be on the safe side and take a little more than the calculated volume of the concentrated reagent, since it is much easier to dilute a concentrated solution than to strengthen one that is too weak. 

For determining the BDI value, 30 mL of milk was boiled for 15 min with 8.9 mL of BDI reagent. 0.25 g of the separated fat was put in a titration tube with 5 mL BDI titration medium. Titration was performed with tetra-n-butyl ammonium hydroxide until the color of the medium changed. 

In an initial step, dibenzo[a,d] cyclohepten-5-one is reacted with the Grignard reagent of 3-di-methylaminopropyl chloride and hydrolyzed to give 5-(3-dimethylaminopropyl)-dibenzo[a,d] -[1,4] cycloheptatriene-5-ol. Then 13 g of that material, 40 ml of hydrochloric acid, and 135 ml of glacial acetic acid is refluxed for 314 hours. The solution is then evaporated to dryness in vacuo and added to ice water which is then rendered basic by addition of ammonium hydroxide solution. Extraction of the basic solution with chloroform and removal of the solvent from the dried chloroform extracts yields the crude product which when distilled in vacuo yields essentially pure 5-(3-dimethylaminopropylidene)-dibenzo[a/f ] [ 1,4] cycloheptatriene, BP 173°C to 177°C at 1.0 mm. 

Acetonitrile (ACN), HPLC grade Ammonium acetate (NH4OAC), reagent grade Ammonium hydroxide, 28%, reagent grade Autosampler vials and septa caps Celite, or equivalent... 

Deliberate production of (vinyl)polystyrene from (toluenesul-foxyethyl)polystyrene or (haloethyl)polystyrenes was best accomplished by quaternization with N,N-dimethylaminoethanol, followed by treatment with base beta-deprotonation is encouraged in the cyclic zwitterionic intermediate. Reaction was faster and cleaner than with other reagents recommended (64, 76, 77) for eliminations, such as alkoxide, diazabicycloundecene or quaternary ammonium hydroxide this new and efficient procedure may find application elsewhere. Hydrometallation or other additions to polymer-bound olefin may prove useful steps in future syntheses by polymer modification. 

In the last decade modifications to the pyrolysis process have been developed to improve analytical efficiency and increase detectability. In the same way as in conventional GC, derivatization reagents may be used to improve the chromatographic separation and response of polar compounds. In order to reduce the time required for the analysis, the risk of contamination and of losing part of the sample, on-line derivatization methods should be preferred and those based on quaternary ammonium hydroxides are certainly the most widely used. 

Table 5.3 Basic solvents. Reagents benzoic acid (acid) and tetra-n-butyl ammonium hydroxide (base)...

MP borohydride catches one equivalent of the titanium catalyst, while the polystyrene-bound diethanolamine resin (PS-DEAM) can scavenge the remaining titanium catalyst. The borohydride reagent also assists in the reductive animation reaction. Final purification of the crude amine product is achieved with a polystyrene-bound toluene sulfonic acid resin scavenger that holds the amine through an ion exchange reaction, while impurities are washed off. The pure amine can be recovered with methanol containing 2M ammonium hydroxide. 

All reagents and solvents were used as received (Sigma-Aldrich) if not stated otherwise. NOL-130 stab initiation mix and preformed, 19 mg graphite-blended l,3,5-trinitro-l,3,5-triazacyclohexane (RDX) pellets were purchased from Day Zimmerman (DZI). Samples prepared for LC-MS analysis were dissolved in ammonium hydroxide and run utilizing a Phenomenex Gemini C6-Phenyl column (4.6 mm X 150 mm) and a mobile phase of 20 mM ammonium acetate in water pH 7.02 at 0.75 ml,-min The HPLC analysis is done using... 

Toluene, dichloromethane, acetic acid, ammonium hydroxide, concentrated H2SO4, 5 N NaOH and 37% HCI were purchased from Mallinckrodt Inc. tetrahydrofuran, tert-butyl alcohol, anhydrous Na2S04, and NaCI were purchased from EM Science potassium tert-butoxide was purchased from Aldrich Chemical Company, Inc. hexanes was purchased from Baxter, and dry O2 was purchased from Air Products. All these reagents were used as received. 

Elemental sulfur is present in most soils and sediments (especially anaerobic), and is sufficiently soluble in most common organic solvents that the extract should be treated to remove it prior to analysis by ECD-GC or GC-MS. The most effective methods available are (1) reaction with mercury or a mercury amalgam [466] to form mercury sulfide (2) reaction with copper to form copper sulfide or (3) reaction with sodium sulfite in tetrabutyl ammonium hydroxide (Jensen s reagent) [490]. Removal of sulfur with mercury or copper requires the metal surface to be clean and reactive. For small amounts of sulfur, it is possible to include the metal in a clean-up column. However, if the metal surface becomes covered with sulfide, the reaction will cease and it needs to be cleaned with dilute nitric acid. For larger amounts of sulfur, it is more effective to shake the extract with Jensen s reagent [478]. 

An interesting alternative to the use of chromium(VI) oxidants for the conversion of 1 to 2 involves the use of a low-valent iron reagent prepared in situ by the action of hydrogen peroxide on an iron(II) complex of 1 (73). Vinblastine (as the free base) is treated with 2 equiv of perchloric acid in acetonitrile at -20°C. Ferrous perchlorate is then added, followed by the addition of excess 30% hydrogen peroxide. Work-up of the reaction mixture with a saturated solution of ammonium hydroxide gives 2 in yields of 35-50% after chromatography. 

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