Outcome 6 Flashcards
what two things do you before performing qc?
- visual inspection for colour and clarity
- calculate assay
during a visual inspection, what must the eluate look like?
- colourless
- clear
- free of particulates
why is it important for the eluate to look that way during a visual inspection?
- should indicate free of foreign material which could be harmful to patients
why is radionuclides purity important? what is it in regards to?
in regards to Mo-99
checking to ensure that there isn’t any Mo-99 in the eluate which can increase patient’s radiation dose
what three things do we do to test for radionuclidic impurities in the generator eluate?
- molybdenum breakthrough test
- phenylhydrazine test
- MCA method
what is the mo-99 breakthrough test?
- testing to see if there is Mo-99 in the eluate
how do we perform the mo-99 b. test?
by the use of special moly breakthrough lead pigs which allow for the mo-99 photons to not attenuate which will allow for the dose calibrator to give readings of mo-99
(has different thickness which attenuates the tc-99m gamma rays)
what is the mca method?
analyzing a sample in an mca to look for energy peaks from other radionuclides other than tc-99m
what is the drawback of the mca method?
must only use a very small sample of eluate in mca
what is the radionuclidic impurity limit?
<0.15 kBq Mo-99/MBq Tc-99m at time of administration
what happens to the ratio of Mo-99 to Tc-99m as time passes?
ratio increases over time as Mo-99 decays slowly and Tc-99m decays quickly
(think tc-99m will be smaller therefore ratio is increasing)
how do you determine expiration times for eluates?
mo-99 breakthrough results or 12 hr max exp time
if the moly breakthrough value is ______ at the time of elution, your eluate can be used until _____.
=<0.042
12 hrs expiry time
what type of contaminant are we looking for when testing chemical purity? why is it important?
Al3+, it can interfere with the attachment of the radionuclide to the pharm. (radiopharm. labelling)
how do we determine chemical purity?
ATA - Orin tricarboxylic acid test
