Formol solution

Transfer 7 to 25 g of sample, accurately weighed, into a 500-mL volumetric flask with the aid of several 50-mL portions of warm, ammonia-free water, dilute to volume with water, and mix. Neutralize 20.0 mL of the solution with 0.2 A barium hydroxide or 0.2 A sodium hydroxide, using phenolphthalein TS as the indicator, and add 10 mL of freshly prepared phenol-phthalein-formol solution (50 mL of 40% formaldehyde con-... 

Contamination with phenolic derivatives, which are always abundant in Fucales this can be avoided by treating the alga with a formolized solution before extraction, so as to induce polymerization of die phenols into insoluble polymers (Mabeau, Kloareg, and Joseleau, 1990). 

A study showed that, if the salt present decomposes at 180°C, its temperature of decomposition reaches 74-80 C when it is in a solution with DMSO. The compounds formed are the ones that are mentioned, but formol is in the form of polymer. There is a substantial gas release during the decomposition. This gas certainly caused the sealed tube to detonate. Another decomposition reaction has been suggested ... 

Cerio, R. and MacDonald, D. (1988) Routine diagnostic immunohistochemical labeling of extracellular antigens in formol saline solution—fixed, paraffin-embedded cutaneous tissue. J. Am. Acad. Dermatol. 19,747-753. 

Synonyms Formaldehyde Solution, Formol, Morbicid, Veracur. 

Synonyms and trade names picronitric acid, 2,4,6-trinitrophenol, trinitrophenol Use and exposure Picric acid is a white to yellowish crystalline substance and highly flammable. It is used in the manufacture of fireworks, matches, electric batteries, colored glass, explosives, and disinfectants. Pharmaceutical, textile, and leather industries also make use of picric acid. Bouin s picro-formol is used as a preservative solution for biological specimens in laboratories. Toxicity and health effects Picric acid causes different adverse effects on the skins of animals and humans, like allergies, dermatitis, irritation, and sensitization. Absorption of picric acid by the system causes headache, fever, nausea, diarrhea, and coma. In high concentrations, picric acid is known to... 

An alternative, simpler, procedure for improving the inflexion in the neutralization of an amino-acid is to add formaldehyde to the solution although this does not affect the acid-titration curve, the one for alkaline titration is changed, as seen in Fig. 107. The effect of the formaldehyde is to increase the strength of the ammonium ion acid which is being titrated, and so the pH inflexion at the equivalence-point becomes much more obvious. This is the basis of the formol titration of amino-acids discovered by Sorensen (1907) approximately 10 per cent of formaldehyde is added to the solution which is then titrated with standard alkali using phenolphthalein as indicator. In the presence of thii concentration of formaldehyde the pH-neutralization curve has a sharp inflexion in the region of pH 9, and so a satisfactory end-point is possible with the aforementioned indicator. 

FORMOL (50-00-0) Forms explosive mixture with air [flash point gas 185°F/85°C flash point solution (methanol content lowers it) 122°-176°F/50°-80°C]. Aqueous solutions (37-55% by weight) are combustible and may explode above their flash points. Aqueous solutions slowly oxidize in air to formic acid. May polymerize unless properly inhibited... 

Formaldehyde Solution, Formalin Formol Morbicid Veracur. A soln of about 37% by wt of formaldehyde gas in water, usually with ]0-15% methanol added to prevent polymerization. This soln is the full strength and also known as Formalin 100% or Formalin 40 which signifies that it contains 40 grams of formaldehyde within 100 ml of the soln. Toxicity data H. F. Smyth et al, J. nd. Hyg. ToxicoL 23, 259 (1941). Prepn of semicarbazone M. Fom-erantz et al, J. Org, Ckem. 47, 2217 (1982). 

The position of equilibrium depends on the nature of the substituent R. In some aldehydes such as chloral, CCI3CHO or formaldehyde HCHO, the equilibrium is shifted towards the diol. In its diol form chloral is known as chloral hydrate and serves as a disinfectant. The trade name of formaldehyde is formol which is actually the water solution of formaldehyde. 

Under the standard conditions formaldehyde is gaseous. However, its molecules can interact with each other by a mechanism similar to nucleophilic attack. The oxygen of the carbonyl group behaves as the nucleophilic atom (see the next scheme). The product of such a reaction is a polymer, the white powder called paraformaldehyde. Hence, formaldehyde can be provided either in the form of the water solution formol or as paraformaldehyde powder. Pure formaldehyde gas for use in chemical reactions can be prepared by heating paraformaldehyde under vacuum. Similarly, the molecules of acetaldehyde can condense into cyclic trimers giving the substance known as paraldehyde. 

Formalin for-m3-l9n, - len [Formalin, a trademark] (1893) (formol) n. HCHO. Formaldehyde gas commercially available as a 37% wt. solution in water with a small amount of methanol for inhibiting polymerization. 

Biopsies were performed without local anesthesia, and were fixed in Bouin s liquid (mixture of an acqueous solution of picric acid, formaldehyde and acetic acid) or in formol (to show eosinophilic leucocytes), then immersed in paraffin and finaly sliced and stained with hematoxylin and eosin according to routine methods. 

Formol titration after the addition of formaldehyde to a solution of the sample at pH 8-9, the free amino acids ate determined by titration with sodium hydroxide solution. 

Formaldehyde is a gas at room temperature. It is soluble in water in any proportion. Industrially, an aqueous solution (called formol) containing 30-40% of aldehyde together with some traces of methanol and formic acid, is used. 

Solutions of formaldehyde, or formol, only have a very moderate action on aluminium. A protective film is generally formed on the surface, which slows down the dissolution of the metal, whether at room temperature or at high temperatures. 

As an example, in a solution containing 37% formaldehyde and 1% methanol, the dissolution rate is 200 JLm per year at room temperature. The presence of other organic products such as methanol or formic acid can slightly increase the dissolution rate [3]. Like formaldehyde, formol is stored and transported in equipment made in aluminium alloy. 

Acid Catalysis. This method is used to produce resins called novolacs by reaction of an excess of phenol (trivalent molecule) with formol (bivalent molecule). In aqueous solution, formol exists mainly as an oligomer of a,co-dihydroxypoly (oxymethylene), whose major component is HO-CH2-OH. In acidic medium, methylene glycol generates a strongly electrophilic carbocationic species... 

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