分散液液微萃取-分光光度法测定食用菌中镉的含量  

Spectrophotometric Determination of Cadmium in Edible Fungi with Separation by Dispersive Liquid-Liquid Microextraction

作　　者：李姌 王蒙[2] 杨亚玲[2] 

机构地区：[1]昆明市第十二中学,昆明650041 [2]昆明理工大学生命科学与技术学院,昆明650500

出　　处：《理化检验（化学分册）》2017年第12期1403-1406,共4页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：取经清洗、粉碎并烘干的样品0.500 0g,用硝酸5mL及过氧化氢3mL,按程序升温模式微波消解。消解液于沸水浴中蒸发至约1mL,用水定容至50mL。取此溶液5.00mL依次加入0.2g·L^(-1) 5-Br-PADAP溶液2.0mL,氨性缓冲溶液(pH 9.0)3.0mL及100g·L^(-1) Triton X-114溶液3.0mL,加水定容至25mL,摇匀,使Cd^(2+)生成络合物,10min后加入辛醇1.0mL,涡旋混合1min,离心5min,吸出下层溶液,取出上层红色有机层,用乙醇定容至3mL,于540nm处用1cm比色皿测得其吸光度。镉的质量浓度在10.00mg·L^(-1)以内与吸光度呈线性关系,检出限(3s)为0.05mg·L^(-1)。加标回收率为93.3%~103%,测定值的相对标准偏差(n=6)小于5.0%。0.500 0 g of the cleaned,crushed and dried sample was digested with HNO_3（5 mL）and H_2O_2（3 mL）in microwave oven under the mode of programmed temperature elevation.After digestion,the sample solution was evaporated to about 1 mL in boiling water bath,and then water was added to make up its volume to 50 mL.5.00 mL of the solution was taken and the following solutions were added in succession：（1） 0.2 g·L^（-1） 5-Br-PADAP：2.0 mL;（2） ammoniacal buffer（pH 9.0）：3.0 mL;and（3） 100 g·L^（-1） Triton X-114：3.0 mL.Then the volume was made up to 25 mL with water and mixed thorough to have the colored complex of Cd^（2＋） formed.After 10 min,1.0 mL of octyl alcohol was added and swirled for 1 min.After centrifugation for 5 min and phase separation,the lower phase was removed and the red colored upper phase was taken and made up its volume to 3 mL with ethyl alcohol.The absorbance of the red solution was measured at 540 nm.Linearity for Cd2＋was kept in the range within 10.00 mg·L-1,and the detection limit（3 s）found was 0.05 mg·L-1.Values of recovery obtained by standard addition method were in the range of 93.3% to 103%.Values of RSDs（n=6）found were less than5.0%.

关 键 词：分光光度法 分散液液微萃取 镉 食用菌 5-BR-PADAP TRITON X-114 

分 类 号：O657.32[理学—分析化学]