title: Urine iodide determination by ion-pair reversed-phase high performance liquid chromatography and pulsed amperometric detection.
abstract: A sensitive and specific ion-pair reversed-phase high performance liquid chromatography (HPLC) method for urinary iodine analysis is described. This method is based on pulsed amperometric detection (PAD) using a silver working electrode (HPLC-PAD), which improves peak shape, electrode stability as well as linearity and reproducibility. A two-step extraction process consisting of solid phase extraction (SPE) and liquid-liquid extraction with dichloromethane was added in order to improve sample purification which is essential with the use of PAD. Treated samples were eluted on a C18 column, using a phosphate buffer containing ion-pairing reagent tetrabutylammonium and 5% MeOH. The calibration standard curves were linear up to 500 μg/L and within-run and between-run coefficients of variation (CVs) were <6% with the quantification limit fixed at 6 μg/L. Accuracy, expressed as recovery, ranged from 94% to 104%. Comparison with the Technicon AutoAnalyzer acid digestion (AA) method resulted in a high correlation (r=0.9916). Due to a low quantification limit and high sample throughput, the proposed technique appears suitable for both epidemiological and clinical follow-up studies.
authors.affiliation: Laboratory of Clinical Chemistry, Centre Hospitalier Universitaire Saint-Pierre, Free University of Brussels, 1000 Brussels, Belgium.
authors.forename: Vo Thanh Phuong
authors.initials: VT
authors.lastname: Nguyen
authors.forename: Virginie
authors.initials: V
authors.lastname: Piersoel
authors.forename: Tarik
authors.initials: T
authors.lastname: El Mahi
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006801:Humans; D007454:Iodides / Q000652:urine*; D057230:Limit of Detection; D012834:Silver / Q000737:chemistry; D016482:Urinalysis / Q000379:methods*
chemical_list: D007454:Iodides; D012834:Silver