The bio-inert quaternary pump comprises an optional solvent cabinet, a vacuum degasser and a four-channel gradient pump. The four-channel gradient pump comprises a high-speed proportioning valve and a pump
assembly. It provides gradient generation by low pressure mixing. A solvent cabinet provides enough space for four one-liter bottles. The pump is optimized for the use of buffer solutions by the active seal wash function,
which cleans pistons and seals.
The bio-inert quaternary pump is based on a two-channel, dual-piston in-series design which comprises all essential functions that a solvent delivery system has to fulfill. Metering of solvent and delivery to the high-pressure side are performed by one pump assembly which can generate pressure up to 600 bar.
Degassing of the solvents is done in a built-in vacuum degasser. Solvent compositions are generated on the low-pressure side by a high-speed proportioning valve (MCGV).
The pump assembly includes a pump head with an active inlet valve and an outlet valve. A damping unit is connected between the two piston chambers. A purge valve including a PTFE frit is fitted at the pump outlet for convenient priming of the pump head.
The pump includes an active seal wash function, which cleans pistons and seals for the use of buffer solutions.
Performance Specifications
| Hydraulic system | Dual piston in series pump with proprietary servo-controlled variable stroke drive, floating pistons and active inlet valve, integrated 4-channel degassing unit |
| Setable flow range | 0.001 – 10 mL/min, in 0.001 mL/min increments |
| Recommended flow range | 0.2 – 10 mL/min |
| Flow precision | < 0.07 % RSD, or < 0.02 min SD whatever is greater, based on retention time at constant room temperature |
| Flow accuracy | ± 1 % or 10 µL/min whatever is greater |
| Pressure | Operating range up to 60 MPa (600 bar, 8700 psi) up to 5 mL/min Operating range up to 20 MPa (200 bar, 2950 psi) up to 10 mL/min |
| Pressure pulsation | < 2 % amplitude (typically < 1.3 %), at 1 mL/min isopropanol, at all pressures > 1 MPa (10 bar) |
| Compressibility compensation | User-selectable, based on mobile phase compressibility |
| Recommended pH range | e 1 – 13 , short term 141 |
| Gradient formation | Low pressure quaternary mixing/gradient capability using proprietary high-speed proportioning valve. Delay volume 600 – 900 µL, dependent on back pressure. |
| Composition range | 0 – 95 % or 5 – 100 %, user selectable |
| Composition precision | < 0.2 % RSD, at 0.2 and 1 mL/min |
| Communications | Controller-area network (CAN), RS-232C, APG Remote: ready, start, stop and shut-down signals, LAN optional |
| Materials in flow path | Titanium, Gold, Platin-Iridium, Sapphire, PEEK, PTFE |
| Active seal wash | Included |
