共振光散射法测定食用油中铁含量

Resonance Light Scattering Method for Determination of Iron Content in Edible Oil

采用微波消解对食用油进行前处理,根据铁(Ⅱ)在氨-氯化铵缓冲溶液中对邻菲啰啉和灿烂黄所产生的共振光散射具有显著增强作用,建立了共振光散射法测定食用油中铁含量的新方法。试验了酸度、邻菲啰啉用量、灿烂黄用量、反应温度和时间对测定的影响,确定了最佳反应条件,还考察了共存离子对测定的干扰情况。在优化的反应条件下,最大共振光散射峰位于360.9 nm,共振光散射增强量与铁(Ⅱ)质量浓度在0～0.25μg/mL范围内线性关系良好,相关系数为0.999 3,检出限为2.8 ng/mL。将该法用于食用油中微量铁的测定,相对标准偏差<3%,回收率为97.3%～102.5%。该方法灵敏准确、简便快速、精密度高、高效环保,完全满足食用油中铁含量的检测要求。

Using microwave method for determination of iron co digestion for pretreatment of edible oil, ntent in edible oil was established,which a new resonance light scattering （RLS） was based on Fe （Ⅱ） obvious enhancing effect on the RLS of phen and brilliant yellow in ammonia - ammonium chloride buffer solution. The optimal reaction conditions were determined after the experiments including acidity, phen and brilliant yellow dosage, reaction temperature and time studied. The interferences from coexistent ions were also investigated. Under optimum reaction conditions,there was a good linear relationship between the enhanced intensity of RLS and the concentration of Fe（Ⅱ） in the range of 0 - 0.25μg/mL with the maximum RLS peak at 360.9 nm and the correlation coefficient of 0.999 3. The detection limit of Fe （Ⅱ） was 2.8 ng/mL. The method was applied to the determination of trace iron in edible oil.RSD was less than 3 %, and recovery was in the range of 97.3 % - 102.5 %. This method was sensitive, accurate, simple, rapid, precise, efficient and environmentally friendly, which could completely meet the analysis requirements of iron content in edible oil.