title: 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.
authors.affiliation: Radiopharmacy Service, Son Espases Hospital, Cra. Valldemossa 79, 07120 Palma de Mallorca, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Villar
authors.forename: Jessica
authors.initials: J
authors.lastname: Avivar
authors.forename: Laura
authors.initials: L
authors.lastname: Ferrer
authors.forename: Margalida
authors.initials: M
authors.lastname: Galmés
authors.forename: Fernando
authors.initials: F
authors.lastname: Vega
authors.forename: Víctor
authors.initials: V
authors.lastname: Cerda