氯酚红探针吸收光谱法快速测定面制食品中的Fe

摘要

A new and accurate absorption spectrometry for quantifying of iron in flour food was developed. In an acidic Tris-HCl buffer medium,an appropriate amount of iron(Ⅲ) was reacted with chlorophenol red,to form a ion association complexes with obvious positive absorption peak and negative absorption peak. The maximum positive absorption wavelength and maximum negative absorption wavelength were at 430 nm and 572 nm re-spectively. The apparent molar absorptivity(κ) were 6.93×104 L/(mol·cm)(positive absorption) and 1.90×105 L/(mol·cm)(negative absorption) respectively. Beer's law was obeyed in the range of 0~1.40 mg/L for iron(Ⅲ) mass concentration.%建立准确测定面制食品中Fe的吸收光谱法。在酸性Tris-HCl缓冲介质中，氯酚红与适量的Fe（Ⅲ）反应生成具有明显正、负吸收峰的离子缔合物，最大正吸收波长和最大负吸收波长分别位于430 nm和572 nm，表观摩尔吸光系数（κ）分别为6.93×104 L/（mol·cm）（正吸收）和1.90×105 L/（mol·cm）（负吸收）。Fe（Ⅲ）的质量浓度在0～1.40 mg/L范围内遵从比尔定律。