Agilent Technologies 1290 Infinity II User Manual page 58

4
Preparing the Module
Solvent Information
PEEK
PEEK (Polyether- Ether Ketones) combines excellent properties regarding
biocompatibility, chemical resistance, mechanical and thermal stability.
PEEK is therefore the material of choice for UHPLC and biochemical
instrumentation.
It is stable in a pH range between 1 – 12, and inert to many common
solvents.
There is still a number of known incompatibilities with chemicals such as
chloroform, methylene chloride, THF, DMSO, strong acids (nitric acid >
10 %, sulphuric acid > 10 %, sulfonic acids, trichloroacetic acid), halogenes
or aequous halogene solutions, phenol and derivatives (cresols, salicylic
acid etc.).
Polyimide
Agilent uses semi- crystalline polyimide for rotor seals in valves and needle
seats in autosamplers. One supplier of polyimide is DuPont, which brands
polyimide as Vespel, which is also used by Agilent.
Polyimide is stable in a pH range between 1 and 10 and in most organic
solvents. It is incompatible with concentrated mineral acids (e.g. sulphuric
acid), glacial acetic acid, DMSO and THF. It is also degraded by
nucleophilic substances like ammonia (e.g. ammonium salts in basic
conditions) or acetates.
Polyethylene (PE)
Agilent uses UHMW (ultra- high molecular weight)- PE/PTFE blends for
yellow piston and wash seals, which are used in 1290 Infinity pumps and
for normal phase applications in 1260 Infinity pumps.
Polyethylene has a good stability for most common inorganic solvents
including acids and bases in a pH range of 1 to 12.5. It is compatible to
many organic solvents used in chromatographic systems like methanol,
acetonitrile and isopropanol. It has limited stability with aliphatic,
aromatic and halogenated hydrocarbons, THF, phenol and derivatives,
concentrated acids and bases. For normal phase applications, the
maximum pressure should be limited to 200 bar.
58 Agilent 1290 Infinity II VWD User Manual