Methods to Analyze Iodine in Salt Moldova

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Methods to Analyze Iodine in SaltMoldova
April 2004 -Arnold TimmerUNICEF Regional
Office
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Methods

• Titration
• Rapid Test kit
• Iodine Checker Machine

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Titration

• Quantitative
• Accurate and reliable
• Inexpensive
• Suitable for fixed labs and trained staff in salt
  companies, external quality control,
  nutrition/public health center

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Rapid Test Kit

• Qualitative yes or no
• Inexpensive
• Easy to perform by untrained staff
• Suitable for small salt producers, salt
  importers, children at school, household surveys
• Not good for quality assurance

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Iodine Checker Machine
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Iodine Checker

• Measuring iodine in salt quickly and precisely
  during it production and distribution can be
  difficult
• Titration methods accurate but are not easily
  applied in salt plants
• The Salt Research Institute of the China National
  Salt Industry Corporation developed the WYD
  Iodine Checker

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Iodine Checker Machine

• Measurement range 10-80 mg/kg
• Method
• Fixed amount of iodized salt (1 g) is dissolved
  in distilled water, then H2SO4 (sulfuric acid)
  and KI (potassium iodide) are added.
• iodine reacts with starch to produce a blue color
• Works on 220 V or batteries
• Cost 300 US

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CDC and Morton Salt Method Comparison
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• Independent testing
• Chemical Engineering, Univ. Toronto, Canada
• results agreed closely with titration
• acceptable accuracy, precision, and
  reproducibility
• China National IDD Reference Laboratory
• assessed in 100 labs in salt plants
• precision slightly lower than that of titration
• batch variance coefficient ?5
• practical to use
• user-friendly