Buchi ELS Detector C-650 Manual de usuario descargar pdf (Pagina 39)

C-650 Operation Manual, Version B

6 Operation

6.2.2 External

To auto-zero the detector, a contact closure signal or a TTL signal is used to short circuit the

contacts. The signal should be at least 1second long, with a maximum current of 20mA at 5V.

If a TTL signal is used please make sure to use the correct polarity identiﬁed on the cable.

6.3 Routine operation of the detector

In general, operation of a Chromatography system with Evaporative Light-Scattering Detection is

similar to operation of the system with other detectors.

During operation of the detector, the following should be considered:

CAUTION

Risk of minor or moderate injury by hot acid fumes.

• Do not operate the system with faulty parts

• Check device setup for proper sealing before use

• Do not inhale process fumes

• Operate the device inside an active fume hood

• Do not move the device or parts of it during operation

NOTICE

Risk of device damage by leaking liquids.

• Do not operate the system with faulty parts

• Check device setup for proper sealing before use

• Make sure that there is a continuous ﬂow of gas through the detector (i.e. no constriction). If

a vacuum is used, ensure that the vacuum effect will not disturb the detector (section 5.4).

• Ensure that the siphon is ﬁlled with liquid at all times. The overﬂow from the siphon should be

collected in a suitable container.

• Make sure that all ﬂow connections are properly tight. In case of any leak, switch off the

pump immediately and remove the liquid.

• Never exceed a gas pressure of greater than 4.5bar (67psi).

• Avoid the use of solvent or compounds that could corrode the detector. The mobile phase is

in contact with glass and PTFE tubing and the evaporation tube is made of stainless steel.

6.4 Optimizing the performance

6.4.1 Selecting the optimum temperature

There are two factors that should be taken into account when selecting the optimum tempera-

ture for the detector:

• Increasing temperature will optimize the evaporation of the mobile phase.

• Decreasing temperature will minimize the decomposition of thermally labile compounds and

the volatilization of semi-volatile compounds.

A very reasonable start is to set the temperature to 60°C if an aqueous mobile phase is used

and 40°C if an organic mobile phase is used (these temperatures are suggested for a ﬂow rate

of 1mL/min). At higher ﬂow rates, more elevated temperatures may be required to minimize the

noise.

1 2 ... 34 35 36 37 38 39 40 41 42 43 44 ... 55 56

Sin comentarios

Buchi ELS Detector C-650 Manual de usuario Pagina 39