Patent ID: 7638338

Claim:
A method for measuring the sample injection volume and the mobile phase delivery rate in an ultra micro-scale liquid phase delivery system, comprising the following steps: (1) selecting a suitable radiochemical substance as a nuclide of the sample to prepare a source solution, based on the micro grade of the volume and the flow rate to be measured; (2) collecting the source solution for a time period t and measuring a the counting rate (R n ) of the collected source solution by a radio activity counting apparatus; and (3) calculating the volume and the delivery rate of the collected source solution by Formula A and Formula B; V total = R n - R B C n × M n × Sp n × Eff n Formula ⁢ ⁢ A f m = R n - R B C n × M n × Sp n × Eff n × t Formula ⁢ ⁢ B wherein, V total is the sample volume, f m is the delivery rate, the counting rate (R n ) is obtained from actual counting of the radioactivity counting apparatus and modified by the half-life period calibration, R B is the background counting rate which is obtained from actual counting of the radioactivity counting apparatus for an empty vial, C n is the concentration of the source solution, M n is the atomic mass of the nuclide, Sp n is the specific activity of the nuclide, Eff n is the counting efficiency of the nuclide which is obtained by standard source calibration of the radio activity counting apparatus, and t is the collection time.