Nitrate with 2,6-dimethylphenol

Photometric determination of nitrate with 2,6-dimethylphenol is conducted in accordance with the German Standard Methods and/or in accordance with DIN 38403, Part 9. In a sulphuric or phosphoric acid solution, nitrate ions react to this reagent within approximately 3 minutes to produce yellowish-coloured 4-nitro-2,6-dimethylphenol. 

As this method is admittedly very suitable for drinking water and ground-water, but not for more highly polluted waters such as effluent. A second method, the classic reductive distillation process, is described in Section 

Cuvettes, Erlenmeyer flasks, transfer pipettes, measuring flasks Nitrate calibrating solution  

1 mg potassium nitrate (dried at 105 C) is diluted in distilled water to 1 litre. 1 ml corresponds to 0.1 mg nitrate ions (NO3 ). 

1 part by volume of sulphuric acid (1.8 g/ml) is mixed with 1 part by volume of phosphoric acid (1.71 g/ml). 

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Chemical/Physical. Under atmospheric conditions, the gas-phase reaction of o-xylene with OH radicals and nitrogen oxides resulted in the formation of o-tolualdehyde, o-methylbenzyl nitrate, nitro-o-xylenes, 2,3-and 3,4-dimethylphenol (Atkinson, 1990). Kanno et al. (1982) studied the aqueous reaction of o-xylene and other aromatic hydrocarbons (benzene, toluene, w and p-xylene, and naphthalene) with hypochlorous acid in the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as expected but was cleaved by chloramine forming cyanogen chloride. The amount of cyanogen chloride formed increased at lower pHs (Kanno et al., 1982). In the gas phase, o-xylene reacted with nitrate radicals in purified air forming the following products 5-nitro-2-methyltoluene and 6-nitro-2-methyltoluene, o-methylbenzaldehyde, and an aryl nitrate (Chiodini et ah, 1993). 

XYLENE-a,a -DI AMINE or m-XYLYLENEDIAMINE (1477-55-0) CjHijNj Combustible Uquid (flash point 273°F/134°C oc Fire Rating 1). Incompatible with organic anhydrides, acids, acid anhydrides acid chlorides acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cellulose nitrate, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, isocyanates, ketones, glycols, nitrates, phenols, vinyl acetate. Exothermic decomposition with maleic anhydride. Increases the explosive sensitivity of nitromethane. On small fires, use dry chemical powder (such as Piuple-K-Powder), foam, or CO extinguishers. XYLENOL 235 (576-26-1) see 2,6-dimethylphenol. 

DIMETHYLPHENOL PHOSPHATE (25155-23-1) Combustible liquid. May react violently with strong oxidizers, antimony(V) pentafluoride. Incompatible with lead diacetate, magnesium, silver nitrate, sulfuric acid, nitric acid, nitrates. 

Dibromo-3,6-dimethylphenol (X = H) upon nitration in acetic add gave the cydohexenone shown while 2,4,5-tribromo-3,6-dimethylphenol (X = Br) afforded the bromo analogue. By aqueous nitratbn of either compound a ring-contracted product was obtained which also resulted through Favorsky rearrangement from the tribromo compound by treatment with aqueous sodium carbonate (ref. 54). 

The standard methods of water analyses used in various countries employ other agents for direct spectrophotometric determination of nitrates, for example, chromotropic acid (4,5-dihydroxy-naphthalene-2,7-disulphonic acid) [13] or 2,6-dimethylphenol and p-fluorophenol [49]. As well the method with salicylate the method with chromotropic acid is also used in the standard methods. 

For the selective alkylation to the < -position of phenol, with methanol, catalysts based on ammonium metavanadate NH4VO3 and ferric nitrate Fe(N03)3 X 9H2O have been suggested. " In this process a raw product of 2,6-dimethylphenol of 64% yield is recovered. Phenol and o-cresol are recycled in this process, as starting materials. 

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