Buchi ELS Detector C-650 Manuel d'utilisateur télécharger pdf (Page 17)

C-650 Operation Manual, Version B

4 Description of function

A plot of log I versus log m provides a linear response. The values of the constants (k and b) are

dependent on a variety of parameters (e.g. the temperature and the nature of the mobile phase).

An inlet to provide additional gas is located immediately before the detector chamber to provide

a concentric shield for the carrier gas. This serves to eliminate diffusion of the carrier gas and

eliminate contamination of the detection chamber.

4.3 Eluent ﬂow splitting

The C-650 detector is designed to work with ﬂow rates from 0.1 to 5mL/min. In preparative chro-

matography applications, the ﬂow rate is mostly higher than 5mL/min. The BUCHI preparative

chromatography systems can deliver ﬂow rates up to 250mL/min. For preparative applications,

the eluent ﬂow rate coming out of the chromatography column must be split into 2 different ﬂow

rates:

• One part (usually about 1mL/min) is directed to the C-650 and this part of the sample is

destructed by the evaporation and diffraction process.

• The other part is directed to the fraction collector to collect the detected compounds.

The working principle is shown below:

Pumping system

Column

Detector

(optional)

ELSD

Fraction

Collector

Flow splitter

≤ 250mL/min

≤ 5mL/min

Fig 4.6: Working principle of the ﬂow splitting

1 2 ... 12 13 14 15 16 17 18 19 20 21 22 ... 55 56

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Buchi ELS Detector C-650 Manuel d'utilisateur Page 17