Developing CHCA/PPD as a novel matrix for enhanced matrix-assisted laser desorption/ionization-mass spectrometry imaging for analysis of antibiotics in grass carp tissues.

Abstract

We have used MALDI-TOF-MSI in positive ion mode for the analysis of quinolones and sulfonamides in grass carps. A novel CHCA/PPD matrix was prepared and applied using a simple method to improve the analysis. Compared with the traditional matrix, CHCA/PPD significantly improved the detection intensity of quinolones and sulfonamides with better sensitivity (17.20%-94.30%) and reproducibility. For demonstration, this novel matrix was successfully applied to visualize enrofloxacin (ENR) in grass carp tissues, with the entire abundance differences clearly observed based on MALDI-MSI. The concentration levels in different tissues were determined, with a calibration curve of 10-2000 μg/ml (R2 > 0.993). This study was the first to introduce CHCA/PPD as a novel matrix, and the classical acid-base mixing was used to improve the ionization effect of the traditional matrix CHCA in MALDI. Based on CHCA/PPD, MALDI-MSI detected ENR in different grass carp tissues for the first time and realized the spatial distribution and concentration detection.