Fig. 1From: Quantitative analysis of vitamin D using m/MALDI-TOF mass spectrometry based on a parylene matrix chipVitamin derivatization using betaine aldehyde and preparation of the parylene matrix chip. a Principle of MALDI-TOF mass spectrometry. b Mass spectra of the organic matrix (CHCA) from repeated measurements. c Preparation scheme of parylene matrix chip and mass spectra of each preparation processBack to article page