The change of sodium ferric EDTA and carbonyl iron was not great, but most of ferric sulfate and ferric ammonium citrate became insoluble during storage.

• 乙二胺四乙酸铁钠和元素羰基铁粉在贮藏过程中变化不大,而硫酸亚铁和柠檬酸铁铵在贮藏过程中绝大部分变成了不溶性铁。