食物中微量碘的离子选择性电极测定法

Determination of Micro-Iodine in Food by Ion-Selective Electrode Method

利用碘离子选择电极，在0．01mol／LNaNO3-0．01mol／L酒石酸为总离子强度调节剂、Na2SO3为还原保护剂、双液接饱和甘汞电极为参比电极的条件下，采用直接电位法测定食物中的碘含量。试验结果表明，本法操作简便、测定快速且准确、灵敏度高、抗干扰能力强。其线性范围为10^-1～10^-7mol／L，检测下限为2．6×10^-8mol／L，回收率为98．3%～101．4％。可广泛用于医药、食品等行业对碘含量的测定。

The iodine content in food was determinated by direct electric potentical method with iodide ion selective electrode, using a mixed solution of 0.01mol/L NaNO3 0.01mol/L tartaric acid as the total ionic strenth adjustment buffer, Na2SO3 as the reduction protection agent , and double junction saturation calomel electrode as the refrence electrode. The results showed that the method is simple in operation, fast in determination with high accuracy, high in sensitivity and strong in interference resistance. Its linear range is 10^- 1 ×10^-7 mol/L and the detection limit is 2. 6 × 10^-8 mol/L, and recovery rate is 98.3%-101.4%. Accordingly, it can be widely used in to determine the iodine contents in medical drugs and foods of the medical and food undertakings, etc.