2H/1H Ratio Analysis of Flavor Compounds by On-Line Gas Chromatography Pyrolysis Isotope Ratio Mass Spectrometry (HRGC-P-IRMS): Benzaldehyde

Isotope ratio monitoring gas chromatography-mass spectrometry of the 2 H/ 1 H ratio by pyrolysis isotope ratio mass spectrometry (P-IRMS) was used to analyze benzaldehyde originating from various sources. Based on the δ 2 H SMOW value of an authentic reference sample determined with an elemental analyzer (EA), the range of reproducibility and linearity was checked. Correct (EA related) and reproducible data were obtained for sample amounts >0.6 μg benzaldehyde (on column). In another series of experiments, the influence of sample preparation, i. e. simultaneous distillation-extraction (SDE) was found to be negligible. The following ranges of δ 2 H SMOW values were determined for benzaldehyde using five types of samples, i. e. (i) synthetic (δ 2 H SMOW -78 to -85‰, ex benzal chloride; +420 to +668‰, ex toluene) and 'natural' (including 'ex-cassia') references (δ 2 H SMOW -83 to -144‰); (ii) bitter almond oils (δ 2 H SMOW -113 to -148‰); (iii) fruits (δ 2 H SMOW -111 to -146‰); (iv) kernels (δ 2 H SMOW -115 to -188‰); and (v) leaves (δ 2 H SMOW -165 to -189‰).