title: Comparison of four alternative radiochemical purity testing methods for 99Tcm-sestamibi.
abstract: Four different methods for determining the radiochemical purity (RCP) of 99Tcm-sestamibi have been proposed to replace the recommended thin-layer chromatography (TLC) method, as the recommended method is inconvenient and time-consuming. The purpose of this study was to compare the recommended TLC method with the four proposed rapid QC methods for 99Tcm-sestamibi: (1) chloroform extraction (CE), (2) mini-paper chromatography with chloroform/tetrahydrofuran (1:1, v/v) (MPC), (3) Waters Sep-Pak alumina N cartridge with 100% ethanol (SPE), and (4) Waters Sep-Pak C18 cartridge with normal saline (SPNS). For RCP values ranging from 21.8 to 98.7% (n = 20), both the CE and SPNS methods produced falsely high RCP values (RCP difference: 14.1 +/- 23.5% for CE and 15.0 +/- 24.9% for SPNS). The MPC and SPE methods were in good agreement (r = 0.98 for MPC and 0.88 for SPE) with the recommended TLC method over the critical RCP range (i.e. 77.0-98.7%, n = 52) (RCP difference: -0.9 +/- 1.2% for MPC and -4.3 +/- 3.2% for SPE). None of the 99Tcm-sestamibi preparations that had been rejected (i.e. RCP < 90%) by the TLC method were accepted by either the MPC or SPE method. However, 4 of the 52 99Tcm-sestamibi preparations with acceptable RCP by the TLC method had unacceptable RCP by the MPC method, whereas 8 of the same 52 preparations were unacceptable by the SPE method.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic, Minnesota 55905, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Hung
authors.forename: M E
authors.initials: ME
authors.lastname: Wilson
authors.forename: M W
authors.initials: MW
authors.lastname: Gebhard
authors.forename: R J
authors.initials: RJ
authors.lastname: Gibbons
mesh_terms: D002725:Chloroform; D002854:Chromatography, Paper; D002855:Chromatography, Thin Layer; D004340:Drug Contamination; D000431:Ethanol; D005069:Evaluation Studies as Topic; D005663:Furans; D011786:Quality Control; D011854:Radiochemistry / Q000379:methods* / Q000592:standards*; D012822:Silicon Dioxide; D012965:Sodium Chloride; D017256:Technetium Tc 99m Sestamibi / Q000032:analysis / Q000592:standards*
chemical_list: D005663:Furans; D000431:Ethanol; C018674:tetrahydrofuran; D012965:Sodium Chloride; D012822:Silicon Dioxide; C042953:octadecyl silane-bonded silica; D002725:Chloroform; D017256:Technetium Tc 99m Sestamibi