Degassing

Maintenance of Degassers

How to get maximum lifetime from your degasser

Modern online degassers used in liquid chromatography, (U)HPLC, and other instruments handling liquids with high precision and accuracy, are fortunately essentially maintenance-free. However, there are a few things to keep in mind not to shorten the lifetime of your online degasser.

Firstly, one should always use a degassing chamber that is compatible with the solvents that will be used. Organic solvents such as hexane, heptane, toluene, tetrahydrofurane (THF), and dichloromethane (DCM), typically demand specially designed degassing chambers. These degassing chambers are often labelled GPC to highlight their suitability in gel permeation chromatography, but they are equally suitable for normal phase and flash chromatography applications where such organic solvents are also employed.

As with any fluidic component it is advised not to leave your degassing chamber with liquid inside when disconnected from use. This is especially important when there are salts or buffer components dissolved into the liquid since they may precipitate. Precipitates will block the flow path and are notoriously very problematic to wash out again. In addition, buffered aqueous solutions exposed to open air may constitute an attractive environment for microbial growth, which can also cause blockage of the flow path.

Finally, it is strongly recommended to always suck solutions through the degassing chambers, rather than pumping or pushing liquids through them. The internal semi-permeable membrane material that allows gases to penetrate while blocking liquids, is designed to withstand a certain pressure difference. That limit may accidentally be exceeded if liquids are pumped too fast into the degassing chamber, which may cause irreparable damage.

Biotech Fluidics is dedicated to supporting our customers and we look forward to guiding you to the most suitable degasser model for your application. Special design options might also be available on request, including for example, high pressure rated degassing chambers.

One-piece fingertight fittings

Popular one-piece fingertight fittings

The original One-Piece Fingertight Fitting was introduced almost 30 years ago and is still one of the most popular fittings offered by Biotech Fluidics for making liquid chromatography fluid path connections of 1/16 inch OD tubing to standard 10-32 coned ports in HPLC instruments. This PEEK fitting (F-120) can hold up to 345 bar (5000 psi) and is convenient and very easy to use since the only tool it requires are your fingers to tighten the fitting into the receiving port. It is available in colours of natural, blue, black, green, red, and yellow. This fitting also comes in a longer version (F-130) which can be more suitable for instrument designs with alternative layouts but requiring similar performance.

In addition, Biotech Fluidics offers a similarly designed Ultra High-Performance version of the One-Piece Fingertight Fitting. This is called VHP PK One-Piece fitting (PK-120BLK) and can withstand temperatures up to 200 °C and pressures up to 827 bar (12 000 psi) thanks to a proprietary PEEK polymer blend. Note that this material may be conductive to electricity and should thus be used with caution in high voltage applications.

Many of the fittings are available in packs of 10 pieces, as indicated by “x” at the end of the product number. Browse our online catalogue from IDEX Health & Science LLC for more information about fittings or contact Biotech Fluidics for guidance and to discuss your application needs.

High-precision Dispensing

High-precision dispensing facilitated by effective degassing
Dissolved gasses present a challenge in most liquid handling situations since off-gassing and the resulting formation of bubbles typically leads to inaccurate results. This is especially troublesome in high-precision dispensing equipment, where exact volumes of chilled solutions must be distributed at high speed during long sequences. The presence of temperature gradients and pressure differences in these setups accelerates bubble formation, which immediately impacts volume accuracy to an unacceptable level. Dispensers are therefore often furnished with alarms that stop and divert the flow if bubbles are detected, which instantly has a negative impact on throughput and productivity.
The most efficient way to reduce formation of bubbles is to resolve the root cause of the problem by removing the excess of dissolved gasses. This is efficiently accomplished by an in-line degasser where a controlled vacuum withdraws dissolved gasses through a gas-permeable membrane that do not allow liquids to pass. The wide range of Biotech DEGASi® PLUS degassers offers flexibility since they are designed to meet several different requirements in terms of volumes, flow rates and solvent compatibility.
The number of daily bubble alarms during dispensing in a production machine carrying nine positive-displacement precision syringes was significantly reduced when the apparatus was equipped with two Biotech DEGASi® PLUS SEMI-PREP 6-channel degassing units. The average number of daily dispensing alarms decreased by nearly 80% when using a degasser and reached a level where this did not significantly disturb the productivity, as displayed in the figure below.

Eliminating Bubble Problems in Ion Chromatography

Dissolved gasses in liquid chromatography eluents may increase background levels and can cause bubble formation that severely disturb the baseline and analyses. When performing ion chromatography separations with suppressed conductivity detection for analysis of anions, the penalties of dissolved gasses are typically poorer signal to noise ratio and consequently worse detection levels. The dissolved gasses can also lead to failed analysis if bubble formation coincide with analyte elution and thus disturb peak integration. A convenient way to eliminate all such problems is to install an online degasser between the eluent reservoir and the pump.
The laboratory at Diduco AB in Umeå (diduco.com) has a number of analytical ion chromatography instruments from several manufacturers installed, and they have fitted Biotech DEGASi™ PLUS Classic degassers with 480 µL internal volume to most of these systems to improve results.
“We have noted significantly more stable output from our ion chromatography analysis after installing degassers”, says Tobias Jonsson, CEO at Diduco AB. “The most distinct effect was in our quality control where we consistently use rather weak hydroxide eluents at high flow rates to test every suppressor we manufacture”.
Data from Diduco’s ion chromatography setup for suppressor quality control shows that the background level decreased about 30% and noise reduced by more than 40% when a degassed was installed. The degasser also completely eliminated the random bubble formation that otherwise would have disturbed these test procedures.

We are very proud to represent IDEX and and their top of the line components for fluidics systems – all to provide our customers with degassers, tubing, fittings, adapters, sensors, filters, valves, HPLC column hardware and more, for a wide variety of fluidic systems, including HPLC and UHPLC instruments.

Degassing Applications

In the article below, written by the research scientist Lars Borm, you see an example of how our valves, degassers and connectors are used in a laboratory environment and how they can be adapted to different customer requirements.

Degassing in a unique automated RNA imaging instrumentation

Our work aims to make high resolution atlases of the mouse and human brain, where we know the location and type of every individual cell in the brain. We do this by imaging the RNA molecules that are present in each cell of the brain with a microscope. The RNA can be seen as an intermediate between the cells’ DNA and the proteins. The information of which specific RNA molecules are present in a cell tells us about the function of the cell. There are thousands of different RNA molecules that can be present in the cell which determine the identity of the cell, and in order to visualize such a high number of targets we perform many cycles of labeling and imaging on the same brain sample.

This takes an enormous amount of work and therefore we have automated the process, by building a fluidic machine that can dispense all the required liquids to the sample and start the imaging. We build three machines that are performing these experiments around the clock and there are many things that can go wrong in such a complex experiment. Air bubbles in the flow cell that holds the brain sample was a common reason why our experiments failed. By putting a bubble-trap and a degasser we can virtually catch and prevent air bubbles going into the flow cell. The degassing is especially important because the samples need to be incubated at different temperatures, and a liquid can quickly out-gas at higher temperatures, forming air bubbles that would have a detrimental effect on the system performance.

Apparatus: A modified analytical DEGASi PLUS standalone degasser with different channel size to optimize degassing efficiency and system dead volume.The valves shown in the photo are IDEX MX Series II™ 10 Position/11 Port Selector Valves.
Author and system designer: Lars Borm | PhD student Linnarsson Lab, Karolinska Institute, Department of Medical Biochemistry and Biophysics, Unit of Molecular Neurobiology, Stockholm, Sweden, web link http://linnarssonlab.org/

Fittings 101 – A Guide to the World of Fittings

Welcome to the World of Fittings!
In this guide you will learn all about the fundamentals of scientific fluidic fittings, accessories and some basics about HPLC as an analytical technique. You probably know a lot about the subjects in this book, but we have found that there is a lack of a publication that provides an overview of the subject and we believe that this handbook can be useful to you in your professional practice. There is also a glossary that covers common words and concepts in the field of fluidics, to make it easier for us all to communicate.

Whether you work with chromatography, SPR technology or any other kind of scientific fluidic system, we hope that this publication will help you understand how fittings works, where they are most suitable and how to choose the right one depending on your fluidic solution.

Below there is a link where you either can read, download a pdf or apply for the printed version.

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BioVersal™ UHPLC Sample Loops

The BioVersal™ sample loops are 100% bioinert, making them ideal when injecting biological or “sticky” samples. These sample loops utilize our unique patented MarvelX technology to auto adjust to various port depths

Pressures up to 1310 bar (131 MPa; 19,000 psi)
No tools required – two fingertight MarvelX™ fittings are included
Zero dead volume and better chromatographic results
Volumes from 5 – 100 µl
Reusable and compatible with all 10-32 coned ports
Inert to almost all organic solvents
PEEK lined stainless steel
Metal-free

DEGASi® HIGH FLOW 1000

Biotech DEGASi® HIGH FLOW 1000

Efficient degassing of liquids at high flow rates has always been a tough challenge. Until now, that is.

Regardless if you work with process chromatography, have sensitive manufacturing processes in biotechnology, make advanced ink jet printing, perform critical dissolution testing, or design sophisticated dispensing equipment, the new Biotech DEGASi® HIGH FLOW 1000 eliminates problems with dissolved gases. With this impressive device, you can efficiently remove bubbles and dissolved gases from your water-based solutions up to 1000 mL/min.

Biotech DEGASi® HIGH FLOW 1000 is equipped with the new superior Systec® DST vacuum pump which ensures ultra-high degasification efficiency with low maintenance. Since this vacuum pump operates with very low vibrations, the Biotech DEGASi® HIGH FLOW 1000 is almost completely silent.

Being based on silicone-membrane technology, Biotech DEGASi® HIGH FLOW 1000 is mainly designed for aqueous liquids in application areas such as:
• Clinical chemistry analyzers
• Dispensing applications
• Dissolution testing
• Process applications
• High-throughput applications
• Ink degassing

Learn more about the new benchmark for high-throughput degasification applications at: DEGASi High Flow 1000

No troubles with bubbles

Degassers improve fluidic instrument precision and reliability by removing dissolved gases from fluids before they outgas and form problem causing bubbles. Three main types of bubble removing products are available:

Teflon AF based degassers offer the widest range of chemical compatibility and are used to eliminate retention shifts and baseline fluctuations.
Silicone based degassers offer the highest flow rate capabilities for water based systems such as diagnostic and life science instrumentation to improve dispense accuracy and reliability.
Poridex based products provide rapid bubble remove for locations where bubble introduction cannot be avoided.

Dissolved gases are actively removed from a flowing liquid stream by vacuum via the IDEX Health & Science AF® membrane.

Degassing - How it works

Dissolved gasses in a fluidic system can often cause troubles. When the pressure or the temperature changes, the dissolved gasses can form bubbles which affect the accuracy, precision and performance of your equipment. On-line degassing is a very efficient way of removing dissolved gasses from the liquid and preventing bubble formation.

Why Degas Your Mobile Phase?

Dissolved air in HPLC mobile phases can result in flow rate instability and baseline disturbance.
Flow rate instability: Non-degassed mobile phase can outgas in the pump head, causing bubbles to be formed and trapped inside the head or check valves. These bubbles can cause flow disturbances and pressure fluctuations, resulting in flow rate instability.
Baseline disturbance: As the mobile phase passes through the column, it experiences a large pressure drop. Non-degassed mobile phase can outgas due to this pressure differential, causing air bubbles to form. Air bubbles passing through or lodging in the
flow cell cause detection disturbances, exhibited as baseline noise.

No Troubles with Bubbles

Biotech AB is specialized in degassing of liquids. With Systec components you can be sure to get degassers with the latest cutting edge technology. Except for our unique range of DEGASi® Standalone degassers, Biotech offers custom made degassing modules to fit your need. Biotech supplies degassing modules to some of the world’s largest instrument manufacturers.

DEBUBBLING

In many low pressure systems, such as diagnostic instruments, bubbles in the fluid stream can cause false detection readings and dispense anomalies. For these systems, the Systec Active Debubbler captures and removes bubbles before they can affect the instrument or the results. Unlike passive bubble traps where bubble removal is dependent on backpressure, the Active Debubbler can be installed before or after a pump and provides consistent debubbling regardless of the system conditions.

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Debubbler implementation

Debubbling - How it works

Dissolved gases and bubbles in system liquids cause dispense volume anomalies in many instruments, negatively affecting both dispense precision and analytical accuracy. Now you have a choice of components for actively removing bubbles with or without also removing dissolved system gases. Online Vacuum Degassing offers operating convenience, high efficiency and low operating costs compared to other common degassing technologies.

Why Debubbling?

In medical analyzers, bubbles interfere with critical volumetric reagent dispenses and cause sample failures, wasting time and money. Because bubbles adhere to nearly every part of a dispensing system, high velocity or induced turbulent flow is often used to displace and discharge bubbles from the flow stream and into a waste area. These alternative processes waste reagents and are time consuming, unpredictable, and may additionally require designing the system to recognize bubbles are present.

No troubles with Bubbles

Biotech AB proudly presents a DEBUBBLER for removal of bubbles in liquids. Improve the precision and accuracy in your instrumentation with our new line of debubblers. The new debubbler can be used in every liquid transferring system where bubbles may occur; Dispensing, DNA-sequencing etc. Custom designed modules upon request. We offer total systems responsibility in the field of degassing and debubbling.

“The world’s first high flow rate,
in-line degasser, for organic solvents”

DEGASi® PREP+

DEGASi PREP PLUS uses a revolutionary new technology that makes it possible to degass organic solutions with higher flows in a cost effective manner. This means that you can increase your capacity at a lower price. The DEGASi® PREP+ is the perfect choice for efficient degassing of many types of liquids at high flow rates, up to 75-100 ml/min per chamber. With four chambers coupled in parallel, a flow of 300-400 ml/min can be used.

"It´s small, smart & silent..."

DEGASi® PREP+ SERIES

Our latest addition to the DEGASi® standalone series is the DEGASi® PLUS. It can be equipped for a wide range of applications, depending on what kind of performance you need.

THE FIRST CHOICE
DEGASi® PLUS is a further development of degassers such as:
- DEGASi®Classic
- DEGASi®Micro
- DEGASi®GPC
- DEGASi®Semi-Prep
FEATURES
- Much smaller footprint, height and weight
- New vacuum pump using a smart board
- Allmost silent
- Available with 1-6 channels
H
- Parallel connected vacuum chambers
- Easier accessibility and visibility
- Easier troubleshooting and replacement of parts
- Short leadtime