Method for determination of Actinium-227 in Actinium-225

A method for determination of Ac-227 in Ac-225, the method comprising:

• providing a purified Ra-225 stock,
• sampling the purified Ra-225 stock to determine Ac-225 and/or Ac-228 content;
• extracting of actinium isotopes from the Ra-225 stock to generate a Stock A;
• resting Stock A to allow the Ac-227 to decay to Th-227;
• adding a Thorium tracer to Stock A;
• chemically isolating Th-227 and the Thorium tracer from other impurities including actinium;
• mounting thorium isotopes onto an alpha counting disc;
• counting the alpha disc using alpha spectroscopy counting equipment to determine Th-227 quantity and tracer recovery %;
• and
• determining an amount of Ac-227 in Stock A by using the counts.

A method for determination of Ac-227 in Ac-225, the method comprising:

• providing a purified Ra-225 stock,
• sampling the purified Ra-225 stock to determine Ac-225 and/or Ac-228 content;
• extracting of actinium isotopes from the Ra-225 stock to generate a Stock A;
• resting Stock A to allow the Ac-227 to decay to Th-227;
• adding a Th-230 tracer to Stock A;
• chemically isolating Th-227 and Th-230 from other impurities including actinium;
• mounting thorium isotopes onto an alpha counting disc;
• counting the alpha disc using alpha spectroscopy counting equipment to determine Th-227 quantity and Th-230 recovery %;
• and
• determining an amount of Ac-227 in Stock A by using the counts.