title: Total iodine quantification in fluids and tissues from iodine- or iodide-supplemented rats by ion chromatography following microwave-assisted digestion.
abstract: BACKGROUND
  Iodine is a crucial component of thyroid hormones, and several reports have shown that iodine per se is implicated in the physiopathology of other organs.
  
  
  METHODS
  Innovative ion chromatography detection following a four-step temperature ramp microwave digestion in 25-50 mM nitric acid was developed to measure total iodine in biological fluids and tissue samples from female Sprague-Dawley rats supplemented with 0.05% molecular iodine (I2) or 0.05% potassium iodide (I(-)) in drinking water.
  
  
  RESULTS
  The reported method allows the measurement of total iodine with a limit of quantification of 13.7 μg L(-1), recoveries of 96.3-100.3%, and intra- and inter-assay variations, of 3.5% and 7.4% respectively. Analysis of biological fluids showed that after 48 hours, iodine-supplemented animals exhibited significantly higher levels of total iodine in both serum and urine compared with those supplemented with iodide. The half-life of iodine in serum and urine measured over the first 48 h showed similar patterns for both the I2 (7.89 and 7.76 hours) and I(-) (8.27 and 8.90 hours) supplements. Differential uptake patterns were observed in tissues after 6 days of supplements, with I(-) preferentially retained by thyroid, lactating mammary gland, and milk, and a slightly but significantly higher capture of I2 in pituitary, ovary, and virgin mammary gland.
  
  
  CONCLUSIONS
  We developed a rapid, selective, and accurate digestion method to process fluid and tissue samples that permits reproducible measurements of total iodine by ion chromatography; iodine or iodide supplement show a similar serum and urine half-life, but organ-specific uptake depends on the chemical form of the iodine supplement.
authors: 1 Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla , Querétaro, México .
authors: Guadalupe
authors: G
authors: Delgado
authors: Carolina
authors: C
authors: Muñoz-Torres
authors: Teresa
authors: T
authors: Orozco-Esquivel
authors: Brenda
authors: B
authors: Anguiano
authors: Carmen
authors: C
authors: Aceves
mesh_terms: D000818:Animals; D002845:Chromatography / Q000379:methods*; D005260:Female; D007454:Iodides / Q000008:administration & dosage; D007455:Iodine / Q000008:administration & dosage / Q000032:analysis*; D007774:Lactation; D057230:Limit of Detection; D008872:Microwaves; D017942:Nitric Acid / Q000032:analysis; D011193:Potassium Iodide / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013696:Temperature; D013961:Thyroid Gland / Q000473:pathology
chemical_list: D007454:Iodides; D011193:Potassium Iodide; D017942:Nitric Acid; D007455:Iodine