24小时热门版块排行榜

返回列表

当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

guoyayun40

铁杆木虫 (正式写手)

应助: 0 (幼儿园)
金币: 8035.4
散金: 174
红花: 3
帖子: 712
在线: 154.1小时
虫号: 732238
注册: 2009-03-27
性别: MM
专业: 色谱分析

[交流] 【求助】浊点萃取的作用已有5人参与

各位做浊点萃取的朋友们，浊点萃取的优点是什么呀

回复此楼

» 猜你喜欢

» 本主题相关价值贴推荐，对您同样有帮助:

1楼 2010-12-11 13:37:16

已阅回复此楼关注TA 给TA发消息送TA红花 TA的回帖

yccxz809

银虫 (正式写手)

应助: 0 (幼儿园)
金币: 618.4
散金: 200
红花: 1
沙发: 1
帖子: 503
在线: 34.1小时
虫号: 928149
注册: 2009-12-14
性别: GG
专业: 光谱分析

★
小木虫(金币+0.5):给个红包，谢谢回帖交流

引用回帖:

Originally posted by guoyayun40 at 2010-12-13 21:36:50:

哪一个更重要一些呀？

The use of
micellar systems such as CPE for separation and preconcentration
has attracted considerable attention in the last few years mainly
because it is in agreement with the “green chemistry” principles.
Green chemistry can be defined as those procedures for decreasing
or eliminating the use or generation of toxic substances for human
health and for the environment [12]. CPE is a green method for the
following reasons: (a) it uses as an extractor media diluted solutions
of the surfactants that are inexpensive, resulting in the economy of
reagents and generation of few laboratory residues; and (b) surfactants
are not toxic, not volatile, and not easily flammable, unlike
organic solvents used in liquid–liquid extraction [13,14].
CPE consist of three simple steps: (1) solubilization of the analytes
in the micellar aggregates; (2) clouding; (3) phase separation
for analysis. When a surfactant solution is heated over a critical
temperature, the solution easily separates into two distinct phases:
one contains a surfactant at a concentration below, or equal to, a
critical micelle concentration; the other is a surfactant-rich phase.
The hydrophobic compounds initially present in the solution and
bound to the micelles are extracted to the surfactant-rich phase.
This phenomenon is observed, in particular, for polyoxyethylene
surfactants and can be attributed to the two ethylene oxide segments
in the micelle that repel each other at low temperature when
they are hydrated and attract each other when the temperature
increases owing to the dehydration.