Substance secondary

Aliphatic and aromatic primary amines on heating with ehloroform and ethanolic potassium hydroxide form isocyanides or earbylamines which are foul smelling substances. Secondary and tertlaiy amines do not show this reaction. This reaction is known as carbylamine reaction or Isocyanlde test and Is used as a test for primary amines. 

Fanconi syndrome (metabolic acidosis secondary to malfunction of proximal renal tubules, resulting in urinary excretion of amino acids, glucose, phosphate, bicarbonate, uric acid, and other substances) secondary to longterm valproic acid has been described in an 8-year-old boy with severe developmental disability (1170). In a review of 10 previous reports of Fanconi syndrome secondary to long-term valproic acid therapy the authors found that all occurred at 4-14 years, all had taken valproic acid for 10 months to 10 years, and symptoms were fully reversible within 2-14 months after withdrawal of valproic acid. Most of the patients (9 of 11) were severely disabled, bedridden, or wheelchair-bound. 

Nucleus Reference substance Secondary reference compound Shift from the primary compound (ppm)... 

Since secondary nucleation is not significantly affected by temperature, it could be concluded that the primary nucleation dominated the scaling mechanism. This is consistent with results from other researchers, who reported that in the precipitation of sparingly soluble substances, secondary nucleation either did not occui [64] or did occur only to a small extent [65, 66]. The number of crystals formed by secondary nucleation during precipitation was substantially lower than those resulting from primary nucleation [67]. 

A basic criterion for this distinction I178J is the presence or absence of a solid phase. While primary nucleation occurs In the absence of solid particles of the crystallized substance, secondary nucleation Is dependent on the presence of crystals. For homogeneous nucleation, no solid phase Is required, while heterogeneous nucleation Is catalytlcally Initiated by any foreign surface. Many details on the mechanisms of secondary nucleation can be found In the literature [152,177,178,214,215,225]. 

Phenomenologically, treatment of a polymer already doped by a primary dopant with an apparently inert substance (secondary dopant) may increase the conductivity of the polymer by several orders of magnitude with concomitant changes in the electronic spectra, and frequently in the degree of crystallinity. Secondary doping differs from primary doping, as mentioned earlier, in that the changes induced by primary/ secondary dopant combination employed may frequently persist, possibly to a reduced extent, even on removal of the secondary dopant. 

The nitrosamines are insoluble in water, and the lower members are liquid at ordinary temperatures. The separation of an oily liquid when an aqueous solution of an amine salt is treated with sodium nitrite is therefore strong evidence that the amine is secondary. Diphenylnitrosoamine is selected as a preparation because it is a crystalline substance and is thus easier to manipulate on a small scale than one of the lower liquid members. For this preparation, a fairly pure (and therefore almost colourless) sample of diphenyl-amine should be used. Technical diphenylamine, which is almost black in colour, should not be employed. 

Dimethyl Sulphate Method for hydroxy compounds and for primary and secondary amines, acid amides, etc. The substance is dissolved or suspended in water, a small excess (above the theoretical) of sodium hydroxide added and then the theoretical quantity of dimethyl sulphate, the mixture being finally shaken without external warming. Methylation is usually rapid, the dimethyl sulphate being converted to methyl hydrogen sulphate... 

The term distillation is applied to vaporisation and subsequent condensation according to (i) it should also be applied to (ii) since it is really the liquid which is converted into vapour and is first formed by condensation. Strictly speaking, the term sublimation should be applied to changes according to (iii). However, in practice, a substance when heated may first melt and then boil, but on cooling it may pass directly from the vapour to the solid the process is then also called sublimation. Indeed the mode of vaporisation, whether directly from solid to vapour or through the intermediate formation of a liquid, is of secondary importance it is the direct conversion of vapour to solid which is really the outstanding feature of sublimation in the laboratory. 

Clemmensen reduction of aldehydes and ketones. Upon reducing aldehydes or ketones with amalgamated zinc and concentrated hydrochloric acid, the main products are the hydrocarbons (>C=0 —> >CHj), but variable quantities of the secondary alcohols (in the case of ketones) and unsaturated substances are also formed. Examples are ... 

Benzoyl chloride test (for primary and secondary amines). Place 0-5 ml. (or 0 5 g.) of the compound, 10 ml. of 5 per cent, sodium hydroxide solution and 1 ml. of benzoyl chloride (CAUTION) in a test-tube, stopper the tube and shake until the odour of benzoyl chloride disappears. Examine the properties of the substance formed. 

Benzenesulphonyl chloride test. Proceed as in the benzoyl chloride test, but use 15-20 ml. of 5 per cent, sodium hydroxide solution. Examine the product when the odour of the sulphonyl chloride has disappeared. (If no reaction has occurred, the substance is probably a tertiary amine.) If a precipitate appears in the alkaline solution, dilute with about 10 ml. of water and shake if the precipitate does not dissolve, a secondary amine is indicated. If the solution is clear, acidify it cautioiosly to Congo red with dilute hydrochloric acid a precipitate is indicative of a primary amine. 

Testosterone promotes muscle growth deepening of the voice the growth of body hair and other male secondary sex characteristics Testosterone is formed from cholesterol and IS the biosynthetic precursor of estradiol the principal female sex hormone or estrogen Estradiol is a key substance m the regulation of the menstrual cycle and the reproductive process It is the hormone most responsible for the development of female secondary sex characteristics... 

Nitrosation (Section 22 15) The reaction of a substance usu ally an amine with nitrous acid Pnmary amines yield dia zonium 10ns secondary amines yield N nitroso amines Tertiary aromatic amines undergo nitrosation of their aro matic ring... 

Much of the energy deposited in a sample by a laser pulse or beam ablates as neutral material and not ions. Ordinarily, the neutral substances are simply pumped away, and the ions are analyzed by the mass spectrometer. To increase the number of ions formed, there is often a second ion source to produce ions from the neutral materials, thereby enhancing the total ion yield. This secondary or additional mode of ionization can be effected by electrons (electron ionization, El), reagent gases (chemical ionization. Cl), a plasma torch, or even a second laser pulse. The additional ionization is often organized as a pulse (electrons, reagent gas, or laser) that follows very shortly after the... 

A big step forward came with the discovery that bombardment of a liquid target surface by abeam of fast atoms caused continuous desorption of ions that were characteristic of the liquid. Where this liquid consisted of a sample substance dissolved in a solvent of low volatility (a matrix), both positive and negative molecular or quasi-molecular ions characteristic of the sample were produced. The process quickly became known by the acronym FAB (fast-atom bombardment) and for its then-fabulous results on substances that had hitherto proved intractable. Later, it was found that a primary incident beam of fast ions could be used instead, and a more generally descriptive term, LSIMS (liquid secondary ion mass spectrometry) has come into use. However, note that purists still regard and refer to both FAB and LSIMS as simply facets of the original SIMS. In practice, any of the acronyms can be used, but FAB and LSIMS are more descriptive when referring to the primary atom or ion beam. 

The three techniques — laser desorption ionization, laser ablation with secondary ionization, and matrix-assisted laser desorption — are all used for mass spectrometry of a wide variety of substances from rock, ceramics, and bone to proteins, peptides, and oligonucleotides. 

Air pollution can be considered to have three components sources, transport and transformations in the atmosphere, and receptors. The source emits airborne substances that, when released, are transported through the atmosphere. Some of the substances interact with sunlight or chemical species in the atmosphere and are transformed. Pollutants that are emitted directiy to the atmosphere are called primary pollutants pollutants that are formed in the atmosphere as a result of transformations are called secondary pollutants. The reactants that undergo transformation are referred to as precursors. An example of a secondary pollutant is O, and its precursors are NMHC and nitrogen oxides, NO, a combination of nitric oxide [10102-43-9] NO, and NO2. The receptor is the person, animal, plant, material, or ecosystem affected by the emissions. 

Tautomerism. Primary and secondary mononitroparaffias are acidic substances which exist ia tautomeric equiUbria with thek nitronic acids. 

General types of physiological functions attributed to quaternary ammonium compounds are curare action, muscarinic—nicotinic action, and ganglia blocking action. The active substance of curare is a quaternary that can produce muscular paralysis without affecting the central nervous system or the heart. Muscarinic action is the stimulation of smooth-muscle tissue. Nicotinic action is primary transient stimulation and secondary persistent depression of sympathetic and parasympathetic ganglia. 

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