Patent ID: 7301018

Claim:
A method for mass spectrometry, comprising binding a probe for mass spectrometry of liquid samples, which is represented by the Formula [I]: R 2 -A-R 1 [I] (wherein R 1 represents an ionic functional group which becomes an ion in a solvent, R 2 represents a structure which can bind to other substances, and A represents a spacer moiety) and further wherein said A is represented by the following Formula [III]: (wherein R 6 represents C 1 -C 20 alkylene with the proviso that not less than one and not more than half of the —CH 2 — units therein may be substituted by one or more groups selected from the group consisting of —O—, —CO— and —NH—, and that said alkylene may be substituted by one or more C 1 -C 20 alkyl; and Ar represents an aromatic ring which may be substituted by 1 to 5 C 1 -C 20 alkyl) to a sample compound in a sample liquid; and subjecting the obtained bound product to mass spectrometry.