Absolute quantitative analysis of endogenous neurotransmitters and amino acids by liquid chromatography-tandem mass spectrometry combined with multidimensional adsorption and collision energy defect

•Multi-dimensional adsorption was firstly used to prepare endogenous substances.•“Collision Energy Defect (CED)” was firstly used to unify mass signal difference.•A comprehensive method was established to measure 28 kinds of NTs and AAs in a single run.•Concentrations of NTs and AAs in MCAO model and sham-operated rats were compared.