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 (2μl) of putrescine, cadaverine and TFAA standards were vaporised at high temperature in a 20cm(3) 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(o)C and an extraction time of 20min. The retention times for the derivatised putrescine and cadaverine were 20.5 and 22.2min, respectively on a capillary column, CP-Sil 8CB; 30m length×0.25mmi.d.×0.25μm film thickness. The correlation coefficients (R(2)) of calibration curves for putrescine and cadaverine were 0.999 and 0.997, respectively over a range of sample masses of 20-350ng, 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.