Carbon, hydrogen, and nitrogen

Perkin Elmer supplies an analyser (model 2400 CHN or PE 2400 series II CHNS/O analysers) suitable for determining these elements in polymers [21-26]. The sample is first oxidised in a pure oxygen environment. The resulting combustion gases are then controlled to exact conditions of pressure, temperature, and volume. Product gases are separated under steady-state conditions and swept by helium or argon into a gas chromatograph for analysis of the components. 

Combustion of polymers in an oxygen-filled flask over aqueous solutions of appropriate reagents converts elements such as halogens, phosphorus and sulfur into inorganic ions. 

Subsequent analysis of these solutions by ion chromatography [27] enables the concentrations of mixtures of these anions (i.e., original elements) to he determined rapidly, accurately, and with great sensitivity. 

Reproduced by kind permission of Perkin Elmer Ltd., Beaconsfield, UK. 

---

Oxygen is present only in small quantities in petroleum as illustrated in Table 1.5, and its concentration is usually determined by subtracting the combined carbon, hydrogen, and nitrogen total from 100. 

This recrystallised acid is pure in the norm y accepted sense of the word, namely it has a sharp m.p. and gives on analysis excellent values for carbon, hydrogen and nitrogen. If however it is subjected to one-dimensional paper chromatography (p. 53), the presence of traces of unchanged anthranilic acid can be detected, and repeated recrystallisation is necessary to remove these traces. 

Hexamefoylenediamine (MM = 116.2 g/mol), a compound made up of carbon, hydrogen, and nitrogen atoms, is used in the production of nylon. When 6.315 g of hexamefoylenediamine is burned in oxygen, 14.36 g of carbon dioxide and 7.832 g of water are obtained. What are foe simplest and molecular formulas of this compound ... 

If the sample is pure (this can generally be checked by thin layer chromatography or gas chromatography) then the elemental analysis values for carbon, hydrogen and nitrogen can be used to obtain element ratios, provided that C, H, N and 0 are the only elements present. 

Hagell GT, Pocklington R (1973) A seagoing system for the measurement of particulate carbon, hydrogen and nitrogen. Report Ser./BI-R-73-14,1-18... 

A test method (ASTM D5291) is available for simultaneous determination of carbon, hydrogen, and nitrogen in petroleum products and lubricants. There are at least three instrumental techniques available for this analysis, each based on different chemical principles. However, all involve sample combustion, components separation, and final detection. 

Patterson, R. K. Automated Pregl-Dumas technique for determining total carbon, hydrogen, and nitrogen in atmospheric aerosols. Anal. Chem. 45 605-609, 1973. 

Nicotine is a second example of a molecule that contains only carbon, hydrogen, and nitrogen ... 

All of todays modern elemental analyzers will determine percentage amounts of carbon, hydrogen, and nitrogen successfully on the vast majority of organo-fluorine compounds without having to change the standard operating conditions of the instruments. 

Coniine, a toxic substance isolated from poison hemlock, contains only carbon, hydrogen, and nitrogen. Combustion analysis of a 5.024 mg sample yields 13.90 mg of C02 and 6.048 mg of H20. What is the empirical formula of coniine ... 

---