Agilent Technologies 1200 series, Reference Manual, Page: 52 / 278

52 Agilent 1200 Series Autosampler Reference Manual
2 Optimizing Performance
Choice of Rotor Seal
Vespel
™
Seal (for standard valves only)
The standard seal has sealing material made of Vespel. Vespel is suitable for
applications using mobile phases within the pH range of 2.3 to 9.5, which is
suitable for the majority of applications. However, for applications using
mobile phases with pH below 2.3 or above 9.5, the Vespel seal may degrade
faster, leading to reduced seal lifetime.
Tefzel
™
Seal (for standard valve only)
For mobile phases with pH below 2.3 or above 9.5, or for conditions where the
lifetime of the Vespel seal is drastically reduced, a seal made of Tefzel is
available (see
“Injection-Valve Assembly” on page 184). Tefzel is more resistant
than Vespel to extremes of pH, however, is a slightly softer material. Under
normal conditions, the expected lifetime of the Tefzel seal is shorter than the
Vespel seal, however, Tefzel may have the longer lifetime under more extreme
mobile phase conditions.
PEEK Seal (for preparative injection valve only)
The preparative injection valve has a sealing material made of PEEK. This
material has high chemical resistance and versatility. It is suitable for
application using mobile phases within a pH between 1 and 14.
N O T E
Strong oxidizing acids such as concentrated nitric and sulfuric acids are not compatible
with PEEK.