Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [99mTc(MIBI)6]+

Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [99mTc(MIBI)6]+ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [99mTc(MIBI)6]+ since impurities such as99mTc-reduced-hydrolyzed (RH),99mTcO4- and [99mTc(cysteine)2]-complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.

Prueba bioquímica al recién nacido / Biochemical test for the newborn

En estudios realizados del screening metabólico se han detectado en nuestra área muestras incorrectas que han sido rechazadas y por tanto ha sido necesaria su repetición. Se explican los objetivos, propósitos y requisitos para la realización de la técnica, y se enumeran los criterios de la OMS para que una enfermedad entre en el plan de screening. Igualmente, se ofrece una actualización acerca de una de las enfermedades que entran en el pesquisaje del screening endocrinometabólico

Detection and estimation of 3,4-dehydroproline.

A method has been described for the detection and estimation of 3,4-dehydroproline using initial oxidation with isatin or H2O2 and subsequent reaction with p-dimethylamino benzaldehyde (Ehrlich reagent). The method is sensitive enough to detect as low as 0.6 micrograms of 3,4-dehydroproline/sq. cm on paper chromatogram. 3,4-dehydroproline could also be estimated by the classical H2O2-oxidation procedure employed for hydroxyproline apparently yielding the same chromophore on a molar basis. However, when estimated by the chloramine-T oxidation method, its sensitivity was only 1/100th of that of 4-hydroxyproline. The usefulness of these procedures in the detection and estimation of 3,4-dehydroproline has been described.