The preparation of99mTc-labelled methionine

On the separation of99mTcO4-,99mTc-DTPA and99mTc-citrate as marker species for the determination of Tc chemical forms in plant material using capillary zone electrophoresis

“…The labelling procedures used are common in nuclear medicine, thus only slight modifications were used as compared to others (Volkert et al, 1982;Mi.inze et al, 1983;Chilton and Thrall, 1990;Ozker et al, 1988Ozker et al, , 1992. 99mTc-diethylenetriaminepentacetic acid (DTPA) was synthesised at room temperature by the addition of 0.1 mL of the SnC1 2 stock solution to 2 mL of an aqueous solution containing 1.7 mL 99mTc0 4 -eluate (10 nmol L-1 ), 0.1 mL 2-morpholinoethanesulfonic acid (MES)-buffer (0.3 mol L-1) pH 5.2 and 0.1 mL DTPA calcium trisodium (0.2 mol L-1 ) pH 5.2.…”

“…99mTc-DTPA was chosen because of both its kinetic stability and its application in an earlier and comparable study (Harms et al, 1996a). The third marker species, 99mTc-citrate, was used because: ( 1) Tc-citrate is a well-known, relative unstable Tc-species used in ligand-exchange labelling procedures ofradiopharmaceuticals; (2) citrate is a wellknown metal complexing ligand; and ( 3) citrate is present in plant materials and in xylem sap in relative high concentrations and has been reported as a component in metal-translocating complexes (Tiffin, 1972;White et al, 1981;Volkert et al, 1982;DePamphilis eta/., 1983;Ozker et al, 1988;El-Kolaly and El-Wetery, 1990;Ozker et al, 1992).…”