Determination of biogenic diamines with a vaporisation derivatisation approach using solid-phase microextraction gas chromatography–mass spectrometry

A gas-phase on-fibre derivatisation method for the determination of putrescine and cadaverine by gas chromatography/mass spectrometry using trifluoroacetylacetone (TFAA) has been studied and optimised. Small amounts (2 μl) of putrescine, cadaverine and TFAA standards were vaporised at high temperature in a 20 cm3 closed SPME vial. The subsequent derivatives were recovered from the headspace of the vial using a PDMS/DVB fibre. The optimised mole ratio for [TFAA]/[Putrescine + Cadaverine] reaction was 22.3/1 with a derivatisation and extraction temperature of 120 oC and an extraction time of 20 min. The retention times for the derivatised putrescine and cadaverine were 20.5 and 22.2 min, respectively on a capillary column, CP-Sil 8CB; 30 m length × 0.25 mm i.d. × 0.25 μm film thickness. The correlation coefficients (R2) of calibration curves for putrescine and cadaverine were 0.999 and 0.997, respectively over a range of sample masses of 20–350 ng, using nonadecane as an internal standard. Putrescine and cadaverine recoveries were determined to be 93.9% and 103.3%, respectively. The method was found to be a straightforward single step procedure that was unaffected by complex sample matrices and was successfully tested on samples of meat, vegetables and cheese.