ASTM E778-15 (R2021) pdf free download.Standard Test Methods for Nitrogen in Refuse-Derived Fuel Analysis Samples.
1 .1 These test methods cover the determination of total Kjeldahl nitrogen in prepared analysis samples of solid forms of refuse-derived fuel (RDF). The procedures measure free ammonia or ammonia formed from the conversion of organic nitrogenous compounds such as amino acids and proteins. However, the procedures may not convert the nitrogenous compounds of some wastes to ammonia. Examples of such compounds that may not be measured are nitro compounds, hydrozones, oxines. nitrates. semicarbazones. pyridines. and some refractory tertiary amines.
1.2 Two alternatives are described for the final determination of the ammonia, the Kjcldahl-Gunning Test Method and the Acid-Titration Test Method.
1.3 The analytical data from these test methods are to be reported as part of the ultimate analysis where ultimate analysis is requested.
1.4 These test methods may be applicable to any waste material from which a laboratory analysis sample can be prepared.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
6. Interferences and Limitations
6.1 Because of the nature of RDF, nitrogenous compounds may be present which will not readily he converted to ammonia by this test method (sec 1. 1). Modifications to the digestion of the waste may enhance the conversion of these nitrogenous compounds to the ammonium salts.
7. Apparatus
7.1 Digestion Unit—An electrical heater of approximately
500-W minimum rating, microwave digester. or a gas burner of comparable capacity. These digestion units shall be provided with adequate means of control to maintain digestion rates as described in 11 .1 (Note 1). Commercially made, multiple-unit digestion racks provided with fume exhaust ducts may be used.
Nom 1—If commercially made electrical heaters are used, auxiliary voltage control equipment such as an autotransformer may be needed to maintain the specified rates of digestion and distillation.
7.2 Distillation Uiii (Fig. 1)—An electrical heater or gas burner as described in 7.1. Either type shall he provided with adequate means of control to maintain rates as described in 11.2. Commercially made, multiple-unit distillation racks provided with water-cooled glass or block tin condensers may be used.
7.3 Co,zcleiz.se, glass. water-cooled, having a minimum jacket length of 500 mm.
7.4 Kjeldahl Digestion Flask, of heat-resistant glass, having a capacity of 500 or 800 mL. Borosilicate glass has been found satisfactory for this purpose.ASTM E778 pdf download.