Selection Of Mobile Phase And Cautions On Handling - Hitachi CHROMASTER 5160 Instruction Manual

3.4.1 Selection of Mobile Phase and Cautions on Handling

(1) Be careful about restriction on use due to characteristics
and temperature of mobile phase to be used. (See Table
3-5 Characteristics of Organic Solvents)
(2) Mobile phase
(a) When performing high sensitivity analysis with a UV
detector, use solvents whose UV absorption
characteristics are especially small. Use solvents for
liquid chromatograph commercially available.
Absorption characteristics of special grade reagents
such as methanol, ethanol and acetonitrile generally
and widely used are greatly different in the short
wavelength range, depending on the manufacturing lot
and the manufacturer. Be careful especially when
performing high sensitivity analysis.
(b) When using mobile phase for liquid chromatograph,
since the connections of pipings of pump and
separation column use stainless steel (SUS316),
solvents or reagents that may corrode stainless steel
may be restricted.
Especially, solvents or solutions which contain halogen
ions such as HCl, KCl, NaCl, NH
reagents. Reagents which may be restricted are
shown in Table 3-2 use the table as a rough standard.
(c) Degas the mobile phase before use without fail.
It is recommended to use a degassing unit because
organic solvents have a specially high content of air,
and the baselines may be fluctuated by bubbles.
Malfunction of check valve and loss of column
efficiency may also be caused. Degassing unit is
especially required for mixing solvents for gradient use.
Degas the solvents before use seeing 3.4.2 Degassing
Mobile Phase.
(3) Wash fluid
(a) Before using a wash fluid, be sure to degas it. If the
degassing of the wash fluid is inadequate, air bubbles
will occur in the flow path of the autosampler, resulting
in a decrease in reproducibility (Refer to 3.4.2)
3 - 61
Cl are typical
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