Nitrogen-chlorine compounds

Chloroamines [334]. Inorganic chloroamines are prepared in pH-controlled reactions by the action of hypochlorous acid or chlorine on ammonium salts, e.g. 

They are widely used as disinfectants and bleaching agents for paper. 

N-Chloroisocyanuric acids, chloroisocyanurates, are prepared by continous reaction of chlorine with isocyanuric acid in aqueous sodium hydroxide at 0-15 C. Their oxidizing and bioactive properties derive from the hypochlorous acid that is slowly released from them in water. They are used as disinfectants for swimming pools, cleaning and sterilizing of bathrooms, laundry bleach and nonshrinking treatment of wool. 

Other organic chloroamines serve as bactericides, disinfectants, chlorinating agents in organic synthesis, and bleaching agents. 

Cyanuric chloride is prepared by chlorinating hydrocyanic acid at 20 - 40 °C in aqueous medium, and after drying, trimerizing to cyanuric acid.The most important cyanuric acid derivates are the aminotriazines, which are used as pesticides, especially as herbicides [335], 

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Alternatively, the hypochlorite ion can be generated by the hydrolysis of organic nitrogen-chlorine compounds. Some of the more important nitrogen-chlorine compounds used in this way are the chlorinated isocya-nurates. These find use in cleansing and dishwasher products. 

Feedstocks come mainly from catalytic cracking. The catalyst system is sensitive to contaminants such as dienes and acetylenes or polar compounds such as water, oxygenates, basic nitrogen, organic sulfur, and chlorinated compounds, which usually require upstream treatment. 

Urea (24), amino acids (25), and creatinine (26) are also decomposed during superchlorination or shock treatment, with formation of N2 and other oxidation products. However, the process is slower than with ammonium ion (see Chloramines and BROMAMINEs). Urea is the principal nitrogen-containing compound in swimming pools. Since it is an amide, it reacts slowly with chlorine, yielding N2, NCl, and NO/ (27). 

The pungent and irritating odor of chloramines is often mistaken for the chlorine odor of swimming pools. Chloramines form from the combination of sodium hypochlorite (added to sterilize the water) and nitrogen-containing compounds that are human waste by-products. 

One advantage of gas chromatography is the availability of detectors which respond specifically to certain types of compound. The best known are the electron capture detector for chlorine compounds and the flame photometric detector for nitrogen and phosphorus compounds. If one wants to detect very small molecules such as water or CSj, the standard flame ionisation detector must be replaced by a thermal conductivity detector. 

Since nitrides have lower heats of formation than oxides, the reaction between chlorine and nitrides will be more complete than between chlorine and oxides. Nitrides react with chlorine to give chlorides and nitrogen. Chlorine, in fact, can displace all negative elements from their compounds, with the exceptions of oxygen and fluorine only. 

The methyl esters can be also determined by GC-FID. Using a 30 m x 0.32 mm ID x 0.25 pm (film thickness) capillary column, such as DB-1701 or equivalent, the compounds can be adequately separated and detected by FID. The recommended carrier gas (helium) flow rate is 35 cm/s, while that of the makeup gas (nitrogen) is 30 cm/min. All of the listed herbicides may be analyzed within 25 min. The oven temperature is programmed between 50 and 260°C, while the detector and injector temperatures should be 300 and 250°C, respectively. The herbicides may alternatively converted into their trimethylsilyl esters and analyzed by GC-FID under the same conditions. FID, however, gives a lower response as compared with ECD. The detection level ranges from 50 to 100 ng. For quantitation, either the external standard or the internal standard method may be applied. Any chlorinated compound stable under the above analytical conditions, which produces a sharp peak in the same RT range without coeluting with any analyte, may be used as an internal standard for GC-ECD analysis. U.S. EPA Method 8151 refers the use of 4,4,-dibromooctafluorobiphenyl and 1,4-dichlorobenzene as internal standards. The quantitation results are expressed as acid equivalent of esters. If pure chlorophenoxy acid neat compounds are esterified and used for calibration, the results would determine the actual concentrations of herbicides in the sample. Alternatively, if required, the herbicide acids can be stoichiometrically calculated as follows from the concentration of their methyl esters determined in the analysis ... 

Highly selective to chlorinated compounds Electrolytic conductivity detector Volatile chlorinated hydrocarbons (EPA 8021) Sulfur and nitrogen compounds may interfere with target analytes. 

Canton, J.H., Sloof, W., Kool, H.J., Struys, J., Pouw, T.J.M., Wegman, R.C.C., Piet, G.J. (1985) Toxicity, biodegradabihty and accumulation of a number of chlorine/nitrogen containing compounds for classification and establishing water quality criteria. Regulat. Toxicol. Pharmacol. 5, 123-131. 

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