PREPARATION AND CONTROL OF /sup 99m/Tc RADIOPHARMACEUTICALS.

Survey of Solvent Extraction 99mTc-Generator Technologies

“…The discontinuous extraction of 99m Tc can be achieved with standard laboratory vessels [ 10,11 ] or a variety of specially designed devices [14,17,19,26,29] and mixing procedures, such as mechanical stirring [31,32], gradual supply of MEK by a capillary and bubbling in air [11,29] or nitrogen [13,14]. A mixing time of 2 to 10 minutes is sufficient to provide efficient separation.…”

“…The filtration is performed on alumina, [e.g. 11,16,18,19,31] or rarely on silica gel [29], or sintered glass, transport of MEK being assured by gravitation [11,19] or applied pressure [15,16,18,31].…”

“…A wide variety of evaporators has been used, from very elementary "open-air" vessels [11,17,19] to glass [18] or stainless steel [24,25] vacuum distillation devices and exceptionally rotary evaporators [29]. Evaporation is performed at 79 °C at atmospheric pressure or in vacuo at lower temperatures down to 40°C, heating with an electric plate, an IR lamp, a thermostat, etc.…”

“…The first MEK 99m Tc generator was elaborated in the late sixties. The design was primitive and consisted of separation funnels adapted for remote handling behind a lead brick wall [10,11 ]. The SET procedure has been steadily improved and is now used in many countries for routine production of 99m Tc.…”