1 research outputs found
A Robust Method for Iodine Status Determination in Epidemiological Studies by Capillary Electrophoresis
Iodine
deficiency is the most common preventable cause of intellectual
disabilities in children. Global health initiatives to ensure optimum
nutrition thus require continuous monitoring of population-wide iodine
intake as determined by urinary excretion of iodide. Current methods
to analyze urinary iodide are limited by complicated sample pretreatment,
costly infrastructure, and/or poor selectivity, posing restrictions
to large-scale epidemiological studies. We describe a simple yet selective
method to analyze iodide in volume-restricted human urine specimens
stored in biorepositories by capillary electrophoresis (CE) with UV
detection. Excellent selectivity is achieved when using an acidic
background electrolyte in conjunction with dynamic complexation via
α-cyclodextrin in an unmodified fused-silica capillary under
reversed polarity. Sample self-stacking is developed as a novel online
sample preconcentration method to boost sensitivity with submicromolar
detection limits for iodide (S/N ≈ 3, 0.06 μM) directly
in urine. This assay also allows for simultaneous analysis of environmental
iodide uptake inhibitors, including thiocyanate and nitrate. Rigorous
method validation confirmed good linearity (<i>R</i><sup>2</sup> = 0.9998), dynamic range (0.20 to 4.0 μM), accuracy
(average recovery of 93% at three concentration levels) and precision
for reliable iodide determination in pooled urine specimens over 29
days of analysis (RSD = 11%, <i>n</i> = 87)