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 Eluent inlet filters prevents dust and other foreign particulate matters from entering the flow path of your liquid chromatography instrument. Such particles would otherwise eventually reach the column inlet, increase the system backpressure and might then also introduce radial flow heterogeneity which could affect peak shape.

Biotech Fluidics offers a range of competently designed inlet filters in different materials and porosities for a variety of solvents and requirements. All of these have a defined homogenous pore size to effectively block particles above a certain size, while letting the mobile phase through without significant pressure increase. The Bottom-of-the-Bottle™ design of these inlet filters make it possible to use mobile phases very efficiently down to the last few millimetres from the bottom of your eluent bottle. Replacement of inlet filters should be performed a couple of times per year and during the regular instrument service routines.

The patented stainless-steel Bottom-of-the-Bottle™ inlet filter features a replaceable filter cup in either 2 or 10 µm pore size that allows solvents to be drawn down to 3.2 mm (1/8 inch) from the bottle bottom. They allow flow rates up to 40 ml/min (10 µm filter) or 10 ml/min (2 µm filter) making it a trusted choice for many situations.

The all-PEEK Bottom-of-the-Bottle™ biocompatible inlet filters are equipped with a bottom withdrawal filter (2 or 10 µm pore size) allowing solvents to be used down to 2 mm (0.08 inch) from the bottom. These inert biocompatible are connected without any fittings and are available for a variety of tubing diameters, while allowing flow rates up to 30 ml/min. In addition, these inlet filter enables the connection of an optional auxiliary helium sparging line.

The inert and biocompatible UHMWPE Bottom-of-the-Bottle™ filter assembly comes with a replaceable filter cup and is an economic alternative enabling solvent withdrawal down to 2.5 mm (0.1 inch) from the bottom of your eluent bottle. These filters allow flow rates up to 5 ml/min although the hydrophobic filter material might require some surface wetting with organic solvents such as methanol or acetonitrile for optimum performance.

Biotech Fluidics also offers additional filters for liquid chromatography, HPLC and other equipment handling delicate fluids. Browse the online catalogue of IDEX Health & Science LLC for more information or contact Biotech Fluidics for guidance and to discuss your application needs.

New Refractive Index Detector

More robust, more sensitive, and more communicative. The new REFRACTi™ MASTER refractive index detector that will be launched by Biotech Fluidics at Analytica in Munich June 21-24 takes RI detection into the modern era of HPLC. The design is meeting all demands of classical liquid chromatography RI applications such as analysis of simple sugars and more complex carbohydrates. The detector can also be applied to HPLC quantification other molecules with poor UV absorbance including alcohols, fatty acids, and polymers.

The REFRACTi™ MASTER RI detector enables an unsurpassed cell temperature control range, from room temperature up to 80 °C, thus greatly facilitating use with highly viscous solvents such as isopropanol, dimethyl formamide (DMF), dimethyl acetate (DMAc) and dimethyl sulfoxide (DMSO).

Stay tuned for more information!

What is the most efficient batch degassing?

The understanding how dissolved gases in HPLC and liquid chromatography can result in problems during detection and pumping is by no means new knowledge. Already 40 years ago, investigations were conducted about this issue while comparing means of solving it using the batch degassing methods available at the time.
It was manifested that bubbling eluents with a gas such as helium, having lower solubility in the mobile phase mixtures compared to the oxygen and nitrogen gases present, was a reasonably efficient way of removing dissolved gases. Almost as powerful was exposing the eluent to an external vacuum, although none of these methods could compare to the most efficient, but highly impractical arrangement of continuously refluxing the solvents. In contrast, especially considering todays rather widespread practice of ultrasonication, was that this approach was remarkably poor at removing dissolved gases from solvents.

“Ultrasonic degassing was
particularly disappointing”

The authors in one scientific paper even explicitly stated that “Ultrasonic degassing was particularly disappointing” after observing that this method only managed to remove one third of the dissolved gases. The citation above and the data on dissolved oxygen gas in methanol plotted in the figure below, were extracted from the scientific paper “Solvent degassing and other factors affecting liquid chromatographic detector stability” by Janet N. Brown et al., published in Journal of Chromatography 204 (1981) 115-122.
Contact Biotech Fluidics to learn how today’s efficient and convenient inline degassers can replace the outdated and ineffective practise of ultrasonication, thus eliminating the source of bubble formation in buffers and mobile phases utilised in HPLC and liquid chromatography.

From all of us to all our clients,
partners and associates,
thank you for your
cooperation during 2021.
We wish you and your families a
Merry Christmas
and a
Happy New Year.
We look forward to a
continued successful 2022.

Stay safe and healthy.