Required materials:
(1) Thin layer chromatography tank.
(2) Ethanol >= 95% (190-200 proof).
(3) Thin layer chromatography plate (Baker-Flex Aluminum Oxide #1 B-F), precut to 2.5 by 7.5 cm.
(4) Radiation detector.
(5) Reconstituted Tc99m Sestamibi solution.
(6) Desiccator
Plate definitions:
(1) top and bottom of the plate: The 2 short sides (2.5 cm)
(2) application point: 1.5 cm from bottom in the vertical midline of plate.
(3) end-point: solvent reaching 1.0 cm from top
(4) run distance: distance between application and end-point
(5) cut-line: across plate at point 4 cm from bottom and 3.5 cm from top
Procedure:
(1) Desiccate the TLC plate (at 100°C for 1 hour, store in desiccator until just before use).
(2) Apply a drop of ethanol to the application point using a syringe with a 22-26 gauge needle. Immediately apply 2 drops of the TC99m Sesamibi solution side-by-side in the ethanol drop at the application point using a 22-26 gauge syringe.
(3) Place the TLC plate in the desiccator and allow the drops at the application to dry. This usually is complete in 10-15 minutes.
(4) While the TLC plate is drying fill the bottom of the chromatography tank to a depth of 3-4 mm with ethanol. Cover the tank and let equilibrate for 10 minutes.
(5) Place the TLC plate in the chromatography tank with the application point down.
(6) Let the solvent rise in the plate until it is 1 cm from the top (run distance 5 cm).
(7) Cut the plate along the cut-line.
(8) Measure the radioactivity in both the upper and lower pieces.
percent radiochemical purity =
= (microCuries counted on the upper piece) * 100% / ((microCuries counted on upper piece) + (microCuries counted on lower piece))
