Method of preparing sample for matrix-assisted laser desorption ionization mass spectrometry and matrix-assisted laser desorption ionization mass spectrometry

A method of preparing a sample for matrix-assisted laser desorption/ionization mass spectrometry comprising the steps of:

• preparing a solution of 2,5-dihydroxy benzoic acid of 40 mg/mL to saturated concentration as a matrix solution;
• and
• dispensing the matrix solution from an inkjet mechanism onto a surface of a sample to be analyzed, to crystallize the 2,5-dihydroxy benzoic acid,
• wherein the sample to be analyzed is a biological specimen held on a surface of a support by sticking, or the sample to be analyzed is a biological sample transferred from a biological specimen to a surface of a support, and
• wherein the biological specimen comprises an intact structure from a living body.