A radioisotope labeled reagent includes a compound having the general formula (I) where a in each occurrence independently is a carbon mass number between 11 and 14 inclusive, b in each occurrence independently is a hydrogen mass number between 1 and 3 inclusive, such that a in each occurrence is not 12 simultaneously with b in each occurrence being 1； L is a leaving group R1SO2&mdash；O&mdash；, R1&mdash；S&mdash；, 12C1H3(12C1H2)n&mdash；S&mdash；R1C(O)O&mdash；, NC&mdash；, (R1)3P&mdash；, XMg&mdash； and Li&mdash；, where n is an integer between 0 and 3 inclusive, where X is chloro, bromo or iodine, where R1 is H, aryl, a substituent containing aryl, C1-C20 alkyl, a substituent containing C1-C20 alkyl, C2-C20 alkenyl, a substituent containing C2-C20 alkenyl, C2-C20 alkynyl, and a substitute containing C2-C20 alkynyl with the proviso that when n is 0, a is 13 and b is 2 and R1 in R1-S is not aryl. L-(aCbH2)naCbH3&emsp；&emsp；(I)
