Hitachi CHROMASTER 5160 Instruction Manual page 338

3.6 Before Analysis
NOTE: For Using Organic Solvent as Mobile Phase
(1) When using an organic solvent, pay attention
to UV cutoff wavelength.
• UV cutoff wavelength refers to a
wavelength below which light will not be
transmitted.
For example, because chloroform has a
cutoff wavelength of 245 nm, it cannot be
used at a wavelength shorter than 245 nm
(e.g., 210 nm).
(2) Boiling point of mobile phase
A solvent having a low boiling point cannot be
used as a mobile phase. For mobile phase,
use a solvent having a boiling point of 55 °C
or higher.
Use of a low boiling point is not only
dangerous, but also gives rise to air bubbles
during suction by the pump, which may
disable the pump from delivering liquid
normally.
(3) For high sensitivity analysis with the UV
detector, use a solvent which absorbs
minimum UV. Generally used high-grade
reagents such as methanol and acetonitrile
absorb UV substantially at shorter
wavelengths. Therefore, a commercially
available solvent for liquid chromatograph
should be used.
Acetonitrile (high grade)
Acetonitrile
(HPLC grade)
Fig. 3-5 Absorption Spectrum of Organic Solvent
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