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Chemistry

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Analytical Chemistry

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Introduction to Separation Methods

Centrifugation for Separating Particles

Description

Centrifugation separates particles in a liquid by using differences in size and density. The sample is placed in centrifugation tubes and spun at high angular velocity. This creates centrifugal force, which makes the different components move at different rates.

After spinning, the supernatant, o...

Transcript

离心是一种通过在离心机中以每分钟高转速旋转,使悬浮颗粒从液体中分离的方法。

 颗粒的沉降速率与其所受离心力成正比。

离心后,颗粒物沉淀至底部,而上清液可被倾倒除去。 

当组分密度相同时,较重的颗粒首先发生沉降。然而,在质量相等的颗粒中,密度较大的颗粒首先沉降。

在差速离心中,较重的颗粒首先在较低转速下被去除。随后逐步提高离心速度,直至分离出目标颗粒。

在密度梯度离心过程中,溶液的密度从管顶向管底逐渐增加。

离心后,每种组分在达到与其密度相等的层时停止移动,从而形成不同的条带。

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