81m
( Kr)
KRYPTON
INHALATION GAS
European Pharmaceia 8.0
Presented by
Anne Cecilie Alvik
Suthatip Ngokpol
Definition
Gaseous mixture of krypton-81m and a
suitable vehicle such as air
2
Production
• Rubidium-81 is produced by proton
irradiation of krypton isotopes or by
helium-3 or helium-4 irradiation of
bromine: 81mKr(p,x)81Rb
79Br(α,2n)81Rb
• Rubidium-81 isolated and retained
= the generator
Rubidium/krypton generator
81Rb
T1/2 (4.58 h)
81mKr
• Krypton-81m is eluted from the
rubidium/krypton generator by a
suitable gas (eg. air) and administered
γ
(11.8 s to 14.4 s)
81Kr
81Br
(stable)
3
Characters
 Appearance : Clear, Colorless gas
 Half-life and nature of radiation:
Chapter 5.7 Table of physical characteristics of radionuclides.
Radionuclide
81 m
Kr
Half life
Type of decay
Energy (MeV)
13.10 s
X
0.012 – 0.014
γ
0.190
4
Identification
A: Gamma-ray
and X-ray spectrometry
Energy: 0.190 MeV of gamma
photon
B: Half-life
11.8 s to 14.4 s
5
Tests
 Radinuclidic purity
•
•
Method: Gamma-ray and X-ray spectrometry.
Elute through water – measure activity – allow
Krypton-81m to decay (5 min) - measure activity
again.
Acceptance criteria: Max 0.1 % of the
radioactive impurities.
 Radioactivity
•
Method: ionisation chamber or gamma ray
spectrometer
6
Storage And labelling
 Applies to the generator
 Store below 25°C.
7
Thank you