Abstract
A simple and reliable method for the determination of NO3-15N or NO2-15N and application of the method to plant material are described. 4-15NO2-2-sec-Butylphenol, which was produced by reaction of 15NO3- and 2-sec-butylphenol in aqueous (5 + 7) sulfuric acid at room temperature for 15min, was subsequently trimethylsilylated to obtain its trimethylsilyl ester. Whereas [15N]-tetrazolophthalazine was produced by reaction of 15NO2- and hydralazine in acidic medium at 70°C for lOmin. The determination of NO3-15N and NO2-15N was achieved after formation of these compounds by gas chromatography-mass spectrometry with selected ion monitoring. The method is specific for NO3-15N or NO2-15N and enables the determination of these anions in plants without any clean-up stage. The detection limits for NO3-15N and NO2-15N in plant material (komatsuna) were 0.75 × 10-6g and 0.13 × 10-6g per sample, respectively. The proposed method was applied to determine NO3-15N and NO2-15N in plants precisely.
