Biotage ELSD-A120, Руководство пользователя

Страница: 36 / 88

36 Biotage
®
ELSD-A120 User Manual
4
Using the Detector
General Considerations
General Considerations
ELSD-A120 should be thought of as a detector like any other designed
for liquid chromatography with an Isolera system. The main
distinguishing feature is the ability to evaporate the solvent from the
cartridge eluent. Therefore, normal system set-up precautions should
be remembered when starting to use the detector. Any solvent
intended for use with the detector should be fully miscible with any
previously used in the liquid chromatograph; if there is any
uncertainty, then a mutually miscible solvent should be run through
the system as an intermediate liquid. The sample loop should also be
flushed with miscible solvent where necessary. The intended eluent
should be thoroughly degassed, contain no non-volatile salts or
material and should be fully compatible with the cartridge(s). Only
connect the detector to the Isolera system using the ELSD-A120
Assembly Kit (P/N 414126
)
supplied with the detector.
ELSD-A120 requires nitrogen of purity >98 %, at an inlet pressure of
60 – 100 psi (4.1 – 6.9 bar). If in-house nitrogen is not available,
then we recommend the use of a nitrogen generator providing a
constant uninterrupted supply of high purity gas. Air can be used with
non-flammable solvent systems. Nitrogen generator is strongly
recommended for best performance. For operation with other inert
gases, contact Biotage for advice.
The eluent of choice should be fully volatile under the chosen detector
parameters – any non-volatilized eluent will increase baseline noise
and reduce sensitivity.
Solvent Recommendations
Any solvent intended for use with ELSD-A120 should be thoroughly
degassed, filtered (0.45 µm) and fully compatible with the
cartridge(s). Solvents that are not properly degassed may cause
problems at nebulization leading to a poor reproducibility.
Non-volatile buffers are not compatible with ELSD-A120 and should
not be used. Only volatile mobile phase additives, such as those listed
in Table 4 on page 37 should be used with the detector.
Tetrahydrofuran (THF) stabilized with BHT may increase the baseline
noise level. Where possible, unstabilized THF should be used with
ELSD-A120.
High boiling point solvents such as N-methylpyrrolidone (NMP),
Dimethylsulphoxide (DMSO), m-Cresol and 1,2,4-Trichlorobenzene
(TCB) are not recommended. Greater care and attention to detector
cleaning procedures should be exercised with these solvents.