~(99)Tc BIOASSAY: A DIRECT COMPARISON OF LIQUID SCINTILLATION RADIATION DETECTION AND ICP-MS MASS DETECTION OF THE ~(99)Tc ISOTOPE

摘要

A means of analyzing ~(99)Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, ~(99)Tc analysis was based on the radiometric detection of the 293 keV E_(Max) beta decay product by liquid scintillation or gas flow proportional counting. A separation scheme for ~(99)Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of ~(99)Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2200 dpm/L. Liquid scintillation results based on an external standard manual quench correction and an automatic quench curve correction method are compared with results obtained by ICP-MS. Each method produced accurate results; however, the precision of the ICP-MS results is superior to that of liquid scintillation results.