title: Flow-injection determination of thyroxine using immobilized enzyme with tris(2,2'-bipyridyl)ruthenium(III) chemiluminescence detection.
abstract: A flow-injection method is reported for the determination of thyroxine based on its enhancement effect on the tris(2,2'-bipyridyl)ruthenium(III) chemiluminescence reaction in the presence of NADH using immobilized alcohol dehydrogenase purified from baker yeast. The limit of detection (3 sigma blank) was 5.0 x 10(-8) M with a sample throughput of 80 h(-1). The calibration graph was linear over the range 0.5 - 10 x 10(-7) M (r2= 0.9988) with the relative standard deviation in the range 1.4 - 3.5% (n = 4). The effect of common excipients used in pharmaceutical preparations, some organic compounds and metal ions was studied. The method was applied to pharmaceutical thyroxine tablets, and the obtained results were not significantly different from the amount quoted.
authors.affiliation: Department of Chemistry, University of Balochistan, Quetta, Pakistan.
authors.forename: Amir
authors.initials: A
authors.lastname: Waseem
authors.forename: Mohammad
authors.initials: M
authors.lastname: Yaqoob
authors.forename: Abdul
authors.initials: A
authors.lastname: Nabi
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000737:chemistry; D000426:Alcohol Dehydrogenase / Q000378:metabolism; D002138:Calibration; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004563:Electrochemistry / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D007854:Lead / Q000737:chemistry; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D008956:Models, Chemical; D009243:NAD / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D012441:Saccharomyces cerevisiae; D013607:Tablets; D013974:Thyroxine / Q000032:analysis / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D009942:Organometallic Compounds; D010087:Oxides; D013607:Tablets; D009243:NAD; C058901:tris(2,2'-bipyridine)ruthenium III; D007854:Lead; C047365:lead oxide; D015082:2,2'-Dipyridyl; D000426:Alcohol Dehydrogenase; D013974:Thyroxine