3P-02 PDF
Chlorophyll aのMALDI 質量分析におけるマトリックスの影響
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been applied to the analysis of Chlorophyll a and extracts from a Maple leaf. The MALDI analysis of Chlorophyll a gave the intense peaks corresponding to molecular ion M+・and protonated analyte [M+H]+ when 1, 5-diaminonaphthalene (1, 5-DAN), 5-amino-1-naphthol (5, 1-ANL) and 1, 5-dihydroxynaphthalene (1, 5-DHN) were used as matrix, while the use of carboxyl group containing matrices such as 2,5-dihydroxybenzoic acid (DHB), sinapinic acid (SA) and a-cyano-4-hydroxycinnamic acid (CHCA) gave the ion peaks of degraded products Pheophytin a (Mg taken off from Chlorophyll a). The degradation of Chlorophyll a may occur by the presence of acidic functional groups in the matrices and solvents used. The mechanisms of the acid-induced degradation and photochemically-induced reduction of Chlorophyll a will be discussed on the basis of MALDI mass spectra and ultraviolet-visible spectroscopy absorption spectra obtained with several matrix and solvent conditions.