1290 Infinity II High-Speed Pumps User Manual 54
3Using the Pump
Solvent Information
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, 1290 Infinity II 
pumps, the G7104C 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 with 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.
Tantalum (Ta)
Tantalum is inert to most common HPLC solvents and almost all acids except 
fluoric acid and acids with free sulfur trioxide. It can be corroded by strong bases 
(e.g. hydroxide solutions > 10 %, diethylamine). It is not recommended for the use 
with fluoric acid and fluorides.