Article ID: 2017.012
A novel derivatization method for the selective and sensitive liquid chromatography (LC)-tandem mass spectrometric (MS/MS) analysis of polyamines (putrescine, cadaverine, spermidine, and spermine) was developed. In this study, to utilize the specific affinity between perfluoroalkyl compounds, called ‘fluorous’ affinity, two to four amino groups in each polyamine molecule were transformed with a relatively short perfluoroalkyl reagent, N-succinimidyl 4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononanoate to achieve the corresponding diperfluoroalkyl- to tetraperfluoroalkyl-derivatives. Compared with the non-fluorous compounds, the fluorophilicity of the multi-fluorous derivatives was sufficient for realizing strong retention on an LC column with a perfluoroalkyl-modified stationary phase. Furthermore, sensitive analysis of these derivatives could be performed using the multiple reaction monitoring mode in positive electrospray ionization-MS/MS. The limits of detection of the polyamines were in the range of 0.31–1.4 nM. The method was validated using human plasma samples. Although the recoveries from spiked human plasma after ultrafiltration were in the range of 66.4–103%, the derivatives could be determined without interference from matrix effects because of their selective retention on the column, which excluded non-fluorous biological matrix components, such as phospholipids. Therefore, this sensitive and selective analysis method was useful for the determination of trace amounts of polyamines in human plasma.