Solvent Recyclers
Improving Sustainability By Reducing Solvent Use
Efficient recycling of isocratic mobile phases in HPLC and other liquid chromatographic setups may save up to 90% of solvent. Biotech Fluidics offer two options for reducing solvent consumption in liquid chromatographic instruments and related fluidic equipment.
Note that solvent recyclers are not recommended for use in gradient applications or other setups where the composition of the fluid changes during the process.
The SPR-200 Solvent Recycler is a stand-alone device, whereas the Biotech SmartSaver™ USB Solvent Recycler requires external computer control. Both solvent-recycling devices operate according to similar principles and contain a three-way valve that can direct the liquid stream to a solvent bottle for reuse or to waste, depending on the input signal and the set parameters. Distinct LEDs on the solvent recyclers indicate if it is in operation and the present position of the directional valve. The wetted materials in both devices are PEEK and PTFE making them compatible with most solvent compositions used in isocratic HPLC applications.
Operational Principle
During operation, the solvent recyclers continuously monitor the analogue output signal from the chromatographic detector. This data is internally converted to a digital signal that is the foundation for the automated decision-making influencing the directional valve. When the signal is above the threshold, the fluid is considered contaminated and thus directed to waste (red waste outlet). When the signal is below the threshold level and the set delay time has passed, the liquid is diverted to the solvent bottle (green recycle outlet).
Delay times are set to ensure that the valve switching is not occurring too early thereby avoiding accidental recycling of contaminated fluid to the solvent bottle. The switching valve in the default position directs the fluid to waste to safeguard the recycled solvent from contamination in case of a power shortage. The solvent recycle devices can accept input signals from autosamplers to autozero the current input signal level at the time of injection.
SPR-200 Solvent Recycler
The SPR-200 Solvent Recycler is a completely stand-alone device with an integrated display to show current input and settings, and control keys to easily set its operational parameters. It is typically externally powered via 5V DC, but can also be powered and programmed via a USB-connected computer running a terminal software application.
SPR-200 Solvent Recycler can reduce the mobile phase in isocratic HPLC by up to 90% by redirecting the uncontaminated mobile phase into the container. The level of the input signal and setting parameters are displayed on a well-read four-digit LCD display. The valve position and the current display mode are indicated by LEDs placed next to the display. Instrument functions are operated via a membrane keyboard with six keys.
Comfortable setting of operating parameters and online device activity tracking can also be operated from a PC using any terminal application.
SPR-200 analog input accepts unipolar and bipolar signals in ranges of ± 1V or ±100 mV alternatively. An analog-to-digital converter provides data for further processing in the embedded microcontroller. TTL (contact closure) input is used for the auto-zero function.
The rear panel of the SPR-200 Solvent Recycler contains the detachable switching valve in the holder and connectors subpanel. The following connections are available (from the left):
- Analog input (yellow)
- TTL Zero input (white)
- Valve connector (blue)
- Micro-B USB connector (black)
- Power switch (green)
SmartSaver™ USB Solvent Recycler
SmartSaver™ USB Solvent Recycler is a computer-controlled device that is connected via USB cable to a personal computer running an installed software application. The USB cable also provides the power required for the Biotech SmartSaver™ USB Solvent Recycler.
SmartSaver™ USB Solvent Recycler is a device dedicated to use in isocratic HPLC. Efficient recycling of the mobile phase may save up to 90% of solvent. Usually, most of the mobile phase is free of contaminants and must not be wasted. With continuous monitoring of the detector signal, the solvent recycler redirects the uncontaminated mobile phase back to the solvent reservoir and saves the solvent and waste disposal costs.
The 3-way valve is switched to the waste or recycle position according to the input signal level. The switching valve is connected to the detector mobile phase output. If the signal level is greater than the signal threshold, the valve is switched to the waste position. The back switching to the recycle position is delayed concerning the time required for liquid transport from the detector cell to the 3-way valve.