Determination of 13C abundance in trace amounts of plant metabolites by the infrared 13CO2 analyzer

The infrared 13CO2 analyzer was improved to measure the 13C abundance in the trace amounts of plant metabolites separated by high performance liquid chromatography (HPLC) . To improve the sensitivity to 12C, the range of wavenumber of 2 360 ± 10 cm-1 was used for 12C determination.Free carbohydrates in corn leaves fed 13CO2 were separated by HPLC and the 13C abundances in sucrose, glucose and fructose were determined by this improved method. The samples containing 10-40, μg of carbon could be successfully analysed.