for injection is injected into a sep pac cartridge while a first glass vial is used to collect the first fluid overflowed then another piston syringe aspirates 5 ml of methanol is followed to flow through the same cartridge using the same way mentioned just now while a second glass vial is used to collect the second fluid overflowed in the end 10 ml of air is injected into the cartridges while a third glass vial is used to collect the third fluid overflowed the radioactivity measurement is used to measure radio activities of the first the second and the third glass containers to obtain results a b c respectively so that an rcp for the sample of in 111 pentetreotide is obtained by using the following formula b a b c u00d7 100 as shown in the figure when using the sep pac cartridge 41 the rcp obtained from the formula b a b c u00d7 100 at the check point of 30 minutes min 60 min 6 hours hr and 24 hr are 97 8 98 6 97 9 and 98 4 respectively from the point of view when using the hplc system 42 and the present invention 43 they obtain the same results as those obtained by using the sep pac cartridge 41 with a correlation greater than 0 99 no matter concerning any result obtained at the check point of 30 min 60 min 6 hr or 24 hr however although the hplc system 42 obtains the 100 of rcp 43 as the present invention does the present invention obtains the analysis on the rcp 43 of the sample more easily and quickly than the hplc.