not yet been controlled satisfactorily to make a single procedure applicable to a wide range of concentrations.
1000 'O0I
.ooT
Figure 7. Oxidation of nitric oxide
ACKNOWLEDGMENT
The authors acknowledge the assistance of Donald R. Strain, California Research Corp., in doing much of the e\perimental work. LITERATURE CITED
(1) * , Bodenstein. 11. Z.. 2. anaew. Chem. 31, 145 (1918).
TIME. MINUTES
that the compression of exhaust gases should provide a rapid and continuous determination if the pressure could be made high enough and if side reactions and other complications could be avoided. Initial experiments w r e carried out using a compression step, followed by an expansion step prior to ineasurement of absorbance. The latter was required in order to avoid corrections due to K204 equilibria and to temperature effects. These shoired
that oxidation \\-as complete but that the measurement amount \vas 1011, frequently less than one half that found by usual analysis. It therefore appears that side reactions occur rapidly a t the high temperatures in the compressor and in the associated storage resen-oir of the equipment. Succeeding euprrinie~itshowed that a combinatio~iof pre:..4wre. residence time, and technique could I)(% found that would gil e the expected results. Honever, these factors have
(2) *Briner, E. W.,Pfeiffer, W.,Malet, G., J . Chim. Phys. 21,25 (1924). (3) Brown, F. B., Crist, R. H., Ibid., 9,
840 (1961 (4) Faith i., TIT. , L., Chem. Eng. Prog. 5 2 ,
342 ilboor. (5) Lunge, G., Berl, E., 2. angew. Chem. 19, 861 (1906). (6) Saltzman, B. E., AYAL. CHEX. 2 6 , 1949 (1954). ( 7 ) Treacy, J. G., Daniels, F., J . Am. Cheni. SOC.77, 2033 (1955). RECEIVED for revieiv January 19, 1062. A4cceptedApril 18, 1962.
Kjeldahl Determination of Nitrogen without Distillation M. H. HASHMI, EHSAN ALI, and MUHAMMAD UMAR West Regional Laboratories C.S.I.R., Lahore, Pakistun A simple and accurate method for Kjeldahl determination of nitrogen without distillation has been developed which does not involve temperature or p H control. The interference due to copper sulfate, mercuric sulfate, and selenium employed as catalysts has been eliminated. The stability of sodium hypobromite has also been improved.
T
HI: estiniation of nitrogen i i PYtremely important to the biochemist. Many modifications of the I
