title: Determination of L-thyroxine in pharmaceutical preparations by flow injection analysis with chemiluminescence detection based on the enhancement of the luminol-KMnO4 reaction in a micellar medium.
abstract: A novel flow injection chemiluminescence (CL) method for the determination of L-thyroxine in the presence of cethyltrimethylammonium bromide (CTMAB) surfactant micelles is developed. The method is based on the significant signal enhancement of L-thyroxine on the luminol-KMnO4 system in alkaline solution sensitized by CTMAB. Parameters affecting the reproducibility and CL detection were optimized systematically. Under the optimum conditions, the net CL intensity versus L-thyroxine concentration was linear in the range of 5.0×10(-8)-3.0×10(-6) mol/L with the detection limit of 8.9×10(-9) mol/L. The sample throughput is calculated to be 140 samples/h and the relative standard deviations (RSDs) for 13 replicate determination of 1.0×10(-6) L-thyroxine is 1.1%. The proposed method was successfully applied for the determination of L-thyroxine in pharmaceutical preparations with satisfactory recoveries in the range of 93.9-105.2%. This rapid, sensitive, and high throughput method would provide a new tool for L-thyroxine analysis.
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, PR China.
authors.forename: Juntao
authors.initials: J
authors.lastname: Cao
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, PR China. Electronic address: liuym9518@sina.com.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Liu
mesh_terms: D004867:Equipment Design; D017022:Flow Injection Analysis / Q000295:instrumentation*; D057230:Limit of Detection; D049449:Luminescence; D008163:Luminescent Measurements / Q000295:instrumentation*; D008165:Luminol / Q000737:chemistry*; D008823:Micelles; D011196:Potassium Permanganate / Q000737:chemistry*; D015203:Reproducibility of Results; D013501:Surface-Active Agents / Q000737:chemistry; D013974:Thyroxine / Q000032:analysis*
chemical_list: D008823:Micelles; D013501:Surface-Active Agents; D011196:Potassium Permanganate; D008165:Luminol; D013974:Thyroxine
keywords: Cethyltrimethylammonium bromide; Chemiluminescence; Flow-injection; Luminol; l-thyroxine