【摘要】 研究了新显色剂5-(4-苯乙酮基偶氮)-8-羟基喹啉(P-AAHQ)与Zn(Ⅱ)的显色反应条件,在阳离子表面活性剂CTMAB存在下,pH 4.0～5.5缓冲介质中,形成稳定的1:2红色配合物,最大吸收波长为520nm,ε=1.01×10~5,含Zn(Ⅱ)量在0～20μg/25ml范围内符合比耳定律。采用氟化钾—磷酸盐混合掩蔽剂,方法用于人发、面食和黄连中微量锌的测定。更多还原

【Abstract】 The chromogenic reaction of zinc （Ⅱ） with 5-（ 4-phenylacetylazo）-8-hydroxyquinoline （p-AAHQ ） was studied- In the presence of CTMAB and at pH 4. 0⁵. 5, Zn（Ⅱ） forms a 1 ’ 2 complex with p-AAHQ. The complex has a maximum absorption at 520nm with an apparent molar-absorptivity of 1. 01×10⁵L ·mol^-1 ·cm^-1. Beer’s law is obeyed in the range of 0²0μg Zn（Ⅱ）/25ml. Fluoride and phosphate are used to e-liminate the interference of Fe³⁺ and A1³⁺. The proposed method has been applied to the determination of trace amounts of Zn（Ⅱ） in human hair, instant noodle and coptis chinensis with satisfactory results.更多还原