PHLEX LDS Flexible Liquid Delivery System The PHLEX LDS converts any HPLC pump to a buffer-free pump. The PHLEX LDS feeds concentrated buffer into the mobile phase stream without changing the total mobile phase flow rate. The final buffer concentration in the mobile phase is adjusted by changing the PHLEX LDS flow rate. The HPLC pump uses only pure organic solvents and water which eliminates salt formation in the main HPLC pump. Without salt formation, seal wear is reduced 5-10 times and pump seals require less changing. Method development is simplified with quick changes from one solvent to another, one buffer to another, and one pH to another. And using pure solvents without premixing eliminates the waste of throwing away premixed mobile phases that didn't work. The pump is suitable for both HPLC and SFC, and provides a simple way of supplying TEA, formic acid or any other modifier to a super critical fluid flow system.

• Eliminate premixing of buffered mobile phases
• Add an additional channel to an existing HPLC
• Use concentrated buffers for reduced bacteria growth
• Deliver reagents for pre- and post-column derivatization
• Convert a dual channel pump to a tertiary pumping system
• Add modifiers such as TEA and formic acid to an SFC system
• Convert an isocratic microbore pump to a high pressure gradient system
• Use as a high-pressure injector in preparative separation chromatography
• Eliminate contamination of HPLC pumps and degassers with buffer components
• Save time in buffer preparation and reduce HPLC solvent waste in method development

Operation | Specifications | Case Study | Phlex Brochure

When an HPLC method requires a buffered mobile phase the buffer is typically combined with water and organic modifier (MeCN, MeOH, THF) to make a premixed mobile phase. If the organic concentration needs to be changed during the run (gradient mode), then the buffer needs to be premixed with both high organic and low organic mobile phase components.

Instead of premixing mobile phases, the patented PHLEX LDS uses a high pressure syringe that is filled with a concentrated buffer solution prior to use. The PHLEX LDS is inserted into the mobile phase fluid stream (blue line), and in delivery mode slowly dispenses buffer (yellow line) into the mobile phase creating a new mobile phase solution (green line). As the syringe pump empties, the plunger movement withdraws mobile phase from the fluid stream and stores it behind the plunger. This simple mechanism insures that the same volume of buffer that enters the fluid stream is the same volume of mobile phase that is removed. Therefore, there is no change in overall flow rate. Additionally, the mobile phase that enters the syringe eliminates buffer crystal buildup behind the plunger.

When the PHLEX LDS syringe is empty, the refill mode switches the high pressure valve and reverses the direction of the plunger. Buffer is drawn into the syringe from the buffer container while the withdrawn mobile phase is pushed to waste. Refill operation takes 1-2 minutes while delivery mode can last many hours with a single fill.

Pump capacity

Max pressure

Max flow rate

Min flow rate

Gradient type

Wetting parts

Liquid ports

Dimensions

Weight

Temperature range

Voltage

Power

Communication

20 mL (high capacity syringe)
4.0 mL (low capacity syringe)

5500 psi (20 mL syringe )
8000 psi (4.0 mL syringe)

15 mL/min (20 mL syringe)
5 mL/min (4.0 mL syringe)

0.0001 mL/min (20 mL syringe)
0.00002 mL/min (4.0 mL syringe)

linear, two stages

SS316, PEEK, PTFE

accepts 10-32 male threaded fittings

11x 13 x 4 inch
28 x 33 x 10 cm

12 lb (6 kg)

4 - 40 degrees C, non-condensing

110 – 250 VAC, 50-60 Hz

50 watt

Serial, CAN, Ethernet, TTL