Objective To investigate a suitable method for food nutrient supplement ferrous lactate dihydrate and trihydrate through the comparison of different methods for moisture content determination. Methods Direct drying method at 105 ℃, direct drying method at 130 ℃, vacuum drying method and Karl Fischer method were used for moisture content determination of ferrous lactate dihydrate and trihydrate. Color and ferric ion (Fe3+) content of the sample were compared before and after drying. Results Direct drying method at 105 ℃, direct drying method at 130℃ and vacuum drying method were suitable for ferrous lactate trihydrate and not suitable for ferrous lactate dehydrate. The moisture content in ferrous lactate dihydrate and trihydrate could be detected by Karl Fischer method. Conclusion Compared with direct drying method at 105 ℃, direct drying method at 130 ℃ and vacuum drying method, Karl Fischer method is more suitable for moisture content determination of ferrous lactate dihydrate and trihydrate. It is recommended that the moisture content should be determined by Karl Fisher method in National food safety standard for food nutrient supplement ferrous lactate.
标题：食品营养强化剂乳酸亚铁中水分含量测定方法探讨
英文标题：Investigation on moisture content determination methods of nutrient supplement ferrous lactate
