Development of a pair of differential H/D isotope-coded derivatization reagents d0/d3-4-(1-methyl-1H-phenanthro[9,10-d]imidazol-2-yl)phenlamine and its application for determination of aldehydes in selected aquatic products by liquid chromatography–tandem mass spectrometry

A new pair of derivatization reagents, d 0 -4-(1-methyl-1 H -phenanthro[9,10- d ]imidazol-2-yl)phenlamine (d 0 -MPIA) and d 3 -4-(1-methyl-1 H -phenanthro[9,10- d ]imidazol-2-yl)phenlamine (d 3 -MPIA) have been designed and synthesized. It was successfully used to label aliphatic aldehydes and the aldehyde derivatives were analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). The new isotope-coded reagents could easily label aldehydes under acidic conditions in the presence of NaCNBH 3 . The target derivatives exhibited intense [M+H] + and regular product ions with electrospray ionization source in positive mode. The d 0 /d 3 -MPIA-aldehydes were monitored by the transitions of [M+H] + → m/z 322 and [M+H] + → m/z 165, and the obtained detection limits were in the range of 0.18–15.9   pg/mL at signal to noise ratio of 3. The global isotope internal standard technology was employed for quantification analysis with d 3 -MPIA-aldehyde as internal standard for corresponding d 0 -MPIA-aldehyde. Excellent linear responses for relative quantification were observed in the range of 1/10–10/1 with coefficients >0.998. The developed method has been applied to the quantification of aliphatic aldehydes in selected aquatic products with RSD<3.6% and recoveries >85.2%.