There is provided a labeling precursor compound represented by the general formula (2): wherein S represents a substrate, L represents a straight 5 alkyl group having 1 to 6 carbon atoms which may contain an ether group, R1 and R2 each independently represent a straight or branched alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted monocyclic or condensed polycyclic aryl group, R3 each independently 10 represent an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and p represents an integer of 0 to 4.
