Methods for measuring iodine in urine and serum

Area of Science:

• Biochemistry
• Public Health
• Analytical Chemistry

Background:

• Assessing iodine nutrition status in populations relies heavily on measuring urinary iodine excretion.
• Various analytical methods exist for urinary iodine determination, each with specific advantages and limitations.

Purpose of the Study:

• To review and compare different methods for measuring urinary iodine.
• To guide the selection of appropriate methods based on study requirements, including epidemiological field studies and research settings.
• To discuss the utility of serum inorganic iodide (SII) measurement.

Main Methods:

• Comparison of established urinary iodine measurement techniques, including rapid field tests, ammonium persulfate oxidation, chloric acid method, Technicon Autoanalyzer, and Paired-Ion Reversed Phase High-Performance Liquid Chromatography (HPLC).
• Evaluation of methods based on factors such as speed, cost-effectiveness, accuracy, sample throughput, and safety.
• Discussion of HPLC as the preferred method for serum inorganic iodide (SII) determination.

Main Results:

• Rapid urinary iodide tests and ammonium persulfate oxidation are suitable for epidemiological field studies due to their simplicity, speed, and cost-effectiveness.
• Automated methods like Technicon Autoanalyzer and HPLC offer high accuracy and efficiency for processing large sample volumes in research settings.
• HPLC is the method of choice for SII measurement, avoiding interference from protein-bound iodine and enabling calculation of absolute iodine uptake.

Conclusions:

• The choice of urinary iodine measurement method should align with the specific needs of the study, balancing practicality with accuracy.
• While clinical relevance of SII is limited, its measurement aids in pathophysiologic studies.
• Accurate iodine status assessment is crucial for public health and requires appropriate analytical methodology.