摘要
提出了一种新的测定奶粉中铁的方法,探索了在酸性介质中,Fe(Ⅲ)与亚铁氰化钾生成普鲁士蓝(PB)反应测定铁的操作条件。结果表明,在pH为2左右配合物最为稳定,最大吸收波长为700nm。Fe(Ⅲ)浓度在0～2.5μg/mL的范围内服从比尔定律,回归方程为:Y=0.0067x-0.0113,相关系数r=0.9987,表观摩尔吸光系数ε=9.83×103mol·L-1·cm-1,Sandell灵敏度为0.0057μg·cm-2,变异系数为0.87%,回收率在96%～103%之间。本法具有操作简便、快速、准确的特点,并且,一般可不经掩蔽干扰离子,直接用于奶粉中铁的测定,结果令人满意。
In this paper,a new method for determination of Fe(Ⅲ)in milk powder is established.It is based on the fact that Fe(Ⅲ)and K 4 Fe (CN) 6 can form blue complexes(PB)in HNO 3 medium.The effects of some factors on the developing reaction have been studied in detail.The results show that the reaction rate is rather fast,the absorption value of this system is stable and the maxium absorption waveleng th is700nm in pH =2acid medium.Beer's law is obeyed in the rang e of 0～2.5μg /mL of Fe(Ⅲ),the calibrated equation is Y=0.0067x-0.0113,the liner correlation coefficient r=0.9987,the molar absorbing coefficientε=9.83×10 3 mol ·L -1 ·cm -1 ,Sandell =0.0057μg /cm -2 ,and the coefficient of recovery is in the range of 96%～103%.This method is simple,quick and accurate.
出处
《食品工业科技》
CAS
CSCD
北大核心
2003年第5期91-93,共3页
Science and Technology of Food Industry
