Automatic and Simple Method for ⁹⁹Tc Determination Using a Selective Resin and Liquid Scintillation Detection Applied to Urine Samples

Abstract

(99m)Tc (6.0067 h half-life) is an artificial radionuclide largely used in diagnostic medicine. Its daughter (99)Tc is a beta emitter of great concern because of its long half-life (2.111 × 10(5) years) and presumed mobile behavior in the environment. To monitor the (99)Tc in urine from treated patients, an automatic Lab-on-valve (LOV) system for separation and preconcentration of (99)Tc was developed. TEVA resin was selected since it retains pertechnetate ion selectively from diluted nitric acid solutions. After elution, (99)Tc is detected using a liquid scintillation counting (LSC) detector. The present method has been successfully applied to urine samples with low (99)Tc content (recoveries between 94-111%). The minimum detectable activity (MDA) of the developed method is 0.1 Bq or 1 Bq L(-1) (expressed as activity concentration), when preconcentrating 100 mL of sample. The high durability of the resin, together with the low amount of resin required (32 mg), the good reproducibility (RSD 2%, n = 5) and the high extraction frequency (up to 12 h(-1)) makes of the present method an inexpensive, precise and fast useful tool for monitoring (99)Tc in urine samples.

Rapid determination of technetium-99 by automatic solid phase extraction and inductively coupled plasma mass spectrometry

“…16 The detection limits in radiometric method depended on the LSC counting time. 17 Another report indicated that 99 Tc was determined by isotope dilution mass spectrometry with 97 Tc as spike. The detection limit of Wang's method by using TIMS for 99 Tc was determined at the concentration below 1 ng g À1 (63 mBq g À1 ), which was much higher than that of this study (1.5 mBq g À1 in 0.25 g sample).…”

Automated ⁹⁰Sr Separation and Preconcentration in a Lab-on-Valve System at Ppq Level

“…Such devices allow the automatic separation and pre-concentration of the analytes prior to the detection, thus increasing reproducibility and repeatability 8 17 18 19 . LOV systems coupled to multisyringe flow pumps have been widely used for the detection of radionuclides, due to the minimization of the reagent consumption and waste generation 8 10 17 18 19 20 . Nevertheless, reported studies regarding online detection at ultra-trace levels are sparse 8 17 .…”

Automated ⁹⁰Sr Separation and Preconcentration in a Lab-on-Valve System at Ppq Level

“…Such devices allow the automatic separation and pre-concentration of the analytes prior to the detection, thus increasing reproducibility and repeatability 8,17,18,19 . LOV systems coupled to multisyringe flow pumps have been widely used for the detection of radionuclides, due to the minimization of the reagent consumption and waste generation 8,10,17,18,19,20 . Nevertheless, reported studies regarding online detection at ultra-trace levels are sparse 8,17 .…”