Phospholipid imaging of zebrafish exposed to fipronil using atmospheric pressure matrix-assisted laser desorption ionization mass spectrometry.

Mass spectrometry imaging can effectively detect and reflect the information of molecular spatial distribution, and has been widely used for in situ analysis of endogenous or exogenous molecules in organisms. The present work applied the atmospheric pressure matrix-assisted laser desorption ionization mass spectrometry (AP-MALDI-MS) in the imaging of whole zebrafish slices exposed to fipronil. The chemical fingerprints in the range of m/z 600-950 showed significant differences in phospholipids between the fipronil exposed and untreated zebrafish groups. The major perturbed phospholipids were identified as PC(34:2), PC(34:1), PC(34:2)+Na, PC(36:4), PC(38:6), and PS(18:0/22:6), PI(18:0/20:4), PI(18:1/20:4) etc. Our results indicated that the exposure of fipronil obviously affected the phospholipid metabolism of zebrafish, especially of the fish eye region. Our work provides a new method or possibility for toxicological study and related metabolic analysis of pesticides in animals.