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粮食、蔬菜中的氟化物测定,国标法一般采用比色法和氟离子选择电极标准曲线法。前者由于样品需要灰化处理,操作繁琐,分析时间长;后者由于氟电极在低浓度范围内其响应斜率与理论斜率不符,而造成的测定误差较大。 作者采用标准加入作图法,校正了稀释效应和响应斜率与理论斜率不符而引起的对测定结果的偏差,而使本方法具有样品处理简单,灵敏度、准确度高的特点,适用于粮食、蔬菜中氟化物的测定。1 仪器与试剂1.1 仪器 氟离子电极和饱和甘汞电极:数字式离子计电
Determination of fluoride in food and vegetables, the national standard method generally uses colorimetric method and fluoride ion selective electrode standard curve method. The former due to the sample needs to be ashing, tedious operation, long analysis time; the latter due to the fluoride electrode in the low concentration range of the response slope and the theoretical slope does not match, resulting in greater measurement error. The author adopts the standard jointing plotting method to correct the deviation of the determination result caused by the dilution effect and the discrepancy between the response slope and the theoretical slope, which makes the method have the advantages of simple sample processing, high sensitivity and high accuracy, and is suitable for the food, vegetable Determination of fluoride. 1 instruments and reagents 1.1 instrument fluoride ion electrode and saturated calomel electrode: digital ion meter