Quality Control Protocol

An assay of the radiochemical purity of the prepared injection can be performed using the following chromatographic procedure. A 35:65 v /v mixture of acetone and dichloromethane should be poured into a chromatography tank to a depth of 1cm. The tank should be covered to allow equilibration to occur.

Mark a Gelman ITLC/SG strip (2cm x 20cm); with a pencil line 3cm from the bottom, make an ink mark line 15cm from the origin, indicating the desired position of the solvent front. Mark pencil lines at 3cm and 12cm from the origin, indicating Rf's of 0.2 and 0.8, respectively.

Using a 1ml syringe and needle, apply a 10µl to 20µl sample of the prepared injection at the origin. Immediately place the strip into the chromatography tank, replacing the cover This sample size will produce a spot with a diameter of 7mm to 10mm. When the solvent reaches the ink line, remove the strip and allow to dry. Cut the strip at the 3cm and 12cm lines and measure the activity using suitable counting equipment. Free Tc-99m-pertechnetate runs to the top' piece, technetium Tc-99m-tetrofosmin runs to the center piece, and any hydrophilic complex impurities remain at the origin of the strip.

Calculate the radiochemical purity from:

% Technetium Tc-99m-tetrofosmin =	Activity of center piece	x 100
	Total activity of 3 pieces

A value of at least 90% should be obtained in a satisfactory preparation.

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