title: Total cyanide mass measurement with micro-ion selective electrode for determination of specific activity of carbon-11 cyanide.
abstract: In this research, we aim to directly measure the specific activity (SA) of the carbon-11 cyanide ([(11)C]CN¯) produced by our in-house built automated [(11)C]HCN production system and to identify the major sources of (12)C-cyanide ((12)CN¯). The [(11)C]CN¯ is produced from [(11)C]CO2, which is generated by the (14)N(p,α)(11)C 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 [(11)C]HCN production system were isolated in order to determine their relative contributions to (12)CN¯ 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 [(11)C]HCN precursor determined using the ISE to the SA of our current [(11)C]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.
authors.affiliation: Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Building 901, Upton, NY 11973, USA. Electronic address: cshea@bnl.gov.
authors.forename: Colleen
authors.initials: C
authors.lastname: Shea
authors.affiliation: Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Building 555, Upton, NY 11973, USA. Electronic address: alexoff@bnl.gov.
authors.forename: David L
authors.initials: DL
authors.lastname: Alexoff
authors.affiliation: Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Building 555, Upton, NY 11973, USA. Electronic address: dohkim@bnl.gov.
authors.forename: Dohyun
authors.initials: D
authors.lastname: Kim
authors.affiliation: Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Building 901, Upton, NY 11973, USA. Electronic address: hoqueruma@gmail.com.
authors.forename: Ruma
authors.initials: R
authors.lastname: Hoque
authors.affiliation: Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Building 901, Upton, NY 11973, USA. Electronic address: mschueller@bnl.gov.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schueller
authors.affiliation: Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Building 555, Upton, NY 11973, USA. Electronic address: fowler@bnl.gov.
authors.forename: Joanna S
authors.initials: JS
authors.lastname: Fowler
authors.affiliation: Biological, Environmental and Climate Sciences Department, Brookhaven National Laboratory, Building 555, Upton, NY 11973, USA. Electronic address: wqu@bnl.gov.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Qu
mesh_terms: D002250:Carbon Radioisotopes / Q000032:analysis*; D003486:Cyanides / Q000032:analysis* / Q000737:chemistry; D017736:Ion-Selective Electrodes; D049268:Positron-Emission Tomography / Q000379:methods
chemical_list: D002250:Carbon Radioisotopes; D003486:Cyanides
keywords: Automated [(11)C]HCN production system; Carbon-11 Cyanide; Micro-ion selective electrode; Specific activity