Iodine in milk: an Ontario study
Two methods for the determination of iodide in milk were compared. The ion-specific electrode (ISE) method correlated well (r2=0.85) with the high performance liquid chromatography (HPLC) method. Mean milk iodide concentrations for retail milks were determined using HPLC. The data suggests that when milk is pooled and processed, differences in iodide concentration are rather small on average. Raw herd milk samples were analyzed over an eight-month period using ISE. The data indicates that when producer milks are pooled for processing, iodide levels in the finished product are similar to those in the raw material. The observed trend toward higher iodide levels in the late fall and winter versus the summer months suggests that season has an effect on milk iodide levels. Geographic region had little impact on iodide levels in the milk supply within the province. Teat-dipping practices using iodophore solutions resulted in the elevation of milk iodide levels.