阳离子交换柱分离-导数光度法测定原油中钒  

DERIVATIVE SPECTROPHOTOMETRIC DETERMINATION OF VANADIUM IN CRUDE OIL——AFTER SEPARATION ON CATION-EXCHANGE COLUMN

作　　者：李萍[1] 张明 赵杉林[1] 

机构地区：[1]辽宁石油化工大学石化学院,抚顺113001 [2]兰州石化公司

出　　处：《理化检验（化学分册）》2003年第4期209-211,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：以 5Br PADAP为显色剂 ,用阳离子交换柱分离干扰离子 ,在波长 6 30nm采用一阶导数光度法测定原油中钒 ,方法灵敏度高 ,摩尔吸光系数为 3.0× 10 5L·mol- 1·cm- 1,较其它光度法测定钒的摩尔吸光系数提高 1～ 2个数量级。对实际样品进行分析并做加标回收试验 ,钒的回收率在97.5 %～ 10 4 .0 %。与ICP AES方法进行对照试验 ,结果相吻合。Crude oil sample was burned and the residue was treated with hydrochloric acid to dissolve V 2O 5 and reduce to its lower valencies of V(Ⅳ) or V(Ⅲ) in the form of vanayl cations as VO 2+ or VO +. After the cation exchange by passing the sample solution through the cation exchange resin in the column, vanayl cations together with other co existing cations were retained on the resin. Then the exchange column was eluted with an acidic solution of hydrogen peroxide, the vanayl cations were oxidized to pentavalent and were eluted from the resin in the form of anions VO - 3 or VO 3- 4, and were thus separated from other cations. Vanadium in the eluate was then determined by 1st derivative spectrophotometry using 5 Br PADAP as color reagent. The absorption maxima of the colored complex was at the wavelength of 630nm. Linearity between the values of d A /d λ and the concencentrations of vanadium was obtained in the range of 0 to 0.6μg·ml -1 of vanadium. The molar absorptivity obtained under the specified condition was 3×10 5L·mol -1 ·cm -1 which was about 1~2 orders higher than conventional photometric methods. Recoveries obtained by the standard addition method were in the range of 97.5%~104.0%. Results obtained by this method were in conformity with those by ICP AES method.

关 键 词：阳离子交换柱 分离 导数光度法 测定 原油 钒 5Br-PADAP 显色剂 

分 类 号：TE622.14[石油与天然气工程—油气加工工程]