吐温-80-PAR显色体系分光光度法测定原油中的钴

Spectrophotometric determination of cobalt in crude oil with Tween-80-4-(2-pyridylazo)-resorcinol chromogenic system

在表面活性剂吐温 80存在下,钴与4 (2 吡啶偶氮)间苯二酚(PAR)形成稳定的有色络合物,其最大吸收波长位于512nm处。于25mL溶液中钴质量在0～40μg范围内服从比尔定律,表观摩尔吸光系数ε=3 4×104。以硫脲掩蔽Fe3+,Cu2+,柠檬酸三钠掩蔽Ni2+,Al3+,Mn2+等金属离子的干扰,所拟方法已成功地用于原油中钴的测定。

In the presence of surfactant Tween80,Co2+ forms a colored and stable complex with PARThe maximum absorption of the complex is at 512nmBeer's law is obeyed in the range from 0 to 40μg/25mL for Co2+The apparent molar absorption coefficient(ε) is 34×104L·mol-1·cm-1Fe3+,Cu2+ are masked by H2NCSNH2,and Ni2+,Al3+ and Mn2+,etc are masked by sodium citrateThe drafted method has been applied to determine cobalt in crude oil successfully