TY - JOUR
T1 - Total cyanide mass measurement with micro-ion selective electrode for determination of specific activity of carbon-11 cyanide
AU - Shea, Colleen
AU - Alexoff, David L.
AU - Kim, Dohyun
AU - Hoque, Ruma
AU - Schueller, Michael J.
AU - Fowler, Joanna S.
AU - Qu, Wenchao
N1 - Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - In this research, we aim to directly measure the specific activity (SA) of the carbon-11 cyanide ([11C]CN-) produced by our in-house built automated [11C]HCN production system and to identify the major sources of 12C-cyanide (12CN-). The [11C]CN- is produced from [11C]CO2, which is generated by the 14N(p,α)11C nuclear reaction using a cyclotron. Direct measurement of cyanide concentrations was accomplished using a relatively inexpensive, and easy to use ion selective electrode (ISE) which offered an appropriate range of sensitivity for detecting mass. Multiple components of the [11C]HCN production system were isolated in order to determine their relative contributions to 12CN- mass. It was determined that the system gases were responsible for approximately 30% of the mass, and that the molecular sieve/nickel furnace unit contributed approximately 70% of the mass. Beam on target (33μA for 1 and 10min) did not contribute significantly to the mass. Additionally, we compared the SA of our [11C]HCN precursor determined using the ISE to the SA of our current [11C]CN- derived radiotracers determined by HPLC to assure there was no significant difference between the two methods. These results are the first reported use of an ion selective electrode to determine the SA of no-carrier-added cyanide ion, and clearly show that it is a valuable, inexpensive and readily available tool suitable for this purpose.
AB - In this research, we aim to directly measure the specific activity (SA) of the carbon-11 cyanide ([11C]CN-) produced by our in-house built automated [11C]HCN production system and to identify the major sources of 12C-cyanide (12CN-). The [11C]CN- is produced from [11C]CO2, which is generated by the 14N(p,α)11C nuclear reaction using a cyclotron. Direct measurement of cyanide concentrations was accomplished using a relatively inexpensive, and easy to use ion selective electrode (ISE) which offered an appropriate range of sensitivity for detecting mass. Multiple components of the [11C]HCN production system were isolated in order to determine their relative contributions to 12CN- mass. It was determined that the system gases were responsible for approximately 30% of the mass, and that the molecular sieve/nickel furnace unit contributed approximately 70% of the mass. Beam on target (33μA for 1 and 10min) did not contribute significantly to the mass. Additionally, we compared the SA of our [11C]HCN precursor determined using the ISE to the SA of our current [11C]CN- derived radiotracers determined by HPLC to assure there was no significant difference between the two methods. These results are the first reported use of an ion selective electrode to determine the SA of no-carrier-added cyanide ion, and clearly show that it is a valuable, inexpensive and readily available tool suitable for this purpose.
KW - Automated [<sup>11</sup>C]HCN production system
KW - Carbon-11 cyanide
KW - Micro-ion selective electrode
KW - Specific activity
UR - http://www.scopus.com/inward/record.url?scp=84929359199&partnerID=8YFLogxK
U2 - 10.1016/j.apradiso.2015.04.014
DO - 10.1016/j.apradiso.2015.04.014
M3 - Article
C2 - 25980658
AN - SCOPUS:84929359199
SN - 0969-8043
VL - 102
SP - 48
EP - 54
JO - Applied Radiation and Isotopes
JF - Applied Radiation and Isotopes
ER -