| 摘要 |
1512124 Nitrate/nitrite determination THERMO ELECTRON CORP 16 March 1976 [17 Sept 1975] 10523/76 Heading G1B A method of measuring the amount of nitrate and/or nitrite compounds in a sample comprises chromatographically separating the nitrate and/or nitrite compounds in the sample from other compounds in the sample by passing the sample in solution in a solvent through a column of a liquid chromatograph, pyrolyzing the portion or portions of the solution containing the nitrate or nitrite compounds to liberate NO in the gaseous phase, and measuring in the gaseous phase the amount of liberated NO. Pyrolysis may be carried out in a uniform diameter, chemically inert tube which is maintained at an appropriate temperature e.g. in the range of 300‹C to 500‹C. After leaving the pyrolyzer, the gas mixture may be fed into a cold trap which is maintained at such a temperature and pressure that all but the nitric oxide content of the gas mixture condenses in said trap. |
