September 6th 2023
Understanding different approaches to Dynamic Light Scattering.
At first sight, goniometer based and enclosed light scattering instruments look vastly different in terms of the bench space they occupy. A new technical article discusses some of the key details and differences between these two approaches to Dynamic Light Scattering (DLS) which might not be immediately obvious to someone interested in learning more about the topic.
Read article.
August 16th 2023
Custom detectors for liquid chromatography.
Drawing on decades of experience, we have created an expanding range of high-performance HPLC, uHPLC and GPC/SEC detectors, pumps, accessories, and software products that can be customized to meet the exact needs of liquid chromatography manufacturers. Our team of knowledgeable technical and engineering staff, based here in Germany, are available to discuss your OEM needs and to provide seamless integration of our technology into your existing or new product.
Want to know more?
August 2nd 2023
Pump problems with gas bubbles.
Many thanks to the editorial team at LaborPraxis for recently publishing our article – ‘Danger recognized, Danger averted.’ The enemy of peristaltic pumps are gas bubbles. In this German language article, you will find out what influence dissolved and undissolved gas has on the performance of these pumps and thus on HPLC, uHPLC and GPC/SEC systems and what can be done about it.
Read article.
July 5th 2023
TESTA Analytical records 1000th social media follower.
Just 5 years ago we started building a thriving social media community. Since May 2018 - we have set about regularly posting new and informative content relevant to the liquid chromatography market that we serve. We are delighted to say that in June we reached our landmark 1000th follower. Thanks to all of you in our social media community for following us on LinkedIn, Twitter, Facebook and Instagram. To help build our community further we’d be delighted if you would share some of our posts with your fellow separation scientists.
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June 14th 2023
Application note: Direct determination of protein molecular weight.
Size-exclusion chromatography (SEC) has traditionally been the ‘go to’ technique for the determination of molecular weights of proteins. However, its usefulness is limited by the time-consuming requirement for calibration of the SEC columns with standards comprising proteins of known molecular weight, but which may not be of the same chemistry as the unknown protein. In a new application note we demonstrate how our Bi-MWA detector enables the determination of the molecular weight of carbonic anhydrase, under standard chromatographic conditions, without column calibration.
Download Application Note.
June 7th 2023
Preparative HPLC users – apply now to beta test our new flow monitoring devices.
TESTA Analytical flowmeters are widely used in analytical chromatography labs as monitoring tools providing continuous measurement of pump performance. We intend, later this year, to launch a new range of Semi-Prep and Prep flowmeters to help chromatographers, using high flow systems, undertake their preparative tasks in a more productive and reliable way. As part of our pre-launch testing, TESTA Analytical is inviting current users of high flow rate preparative HPLC systems, to apply to enter our Beta test program and be among the first organizations to appreciate the value of flow monitoring in Prep Chromatography.
Apply now.
May 4th 2023
Why choose a Rapid Scanning UV detector rather than a Diode Array UV detector?
The UV detector is one of the most used chromatography detectors today because of its reliability, ease of use, and universal response to chromophoric compounds, including most pharmaceuticals. The advantages of using a Diode Array UV detector for analytical HPLC are well documented. However, for applications that involve delicate samples, the high UV energy output of a Diode Array UV detector can be a disadvantage. For such applications, a detector which does not apply the full UV energy load to the sample the whole time is a better alternative. The TESTA Analytical Rapid Scanning UV detector is such an alternative. Capable of measuring the absorption signal for up to 4 wavebands simultaneously, our Rapid Scanning UV is the perfect detector for applications involving thermallylabile samples.
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April 20th 2023
Considering development of a new chromatography detector?
Did you know that TESTA Analytical is the name behind a growing number of market leading HPLC and GPC/SEC systems? With decades of chromatographic expertise and knowledge, TESTA Analytical has proven itself as a pioneering developer and OEM supplier of differential refractive index, viscometry, rapid scanning UV-visible, dn/dc, flowmeter and gas bubble detectors that set new standards for performance, stability and reliability. To learn more about what makes us a great OEM design and development partner.
Download our OEM services brochure.
March 29th 2023
Looking to give your liquid chromatography system a competitive edge?
An optimised separation is often considered to be the defining quality of an HPLC, UHPLC, GPC/SEC, Ion Chromatography or FPLC system. High performance separation alone however does not supply answers, it just creates the correct preconditions whereby an optimised chromatography detector is able to reveal the 'secrets' of your sample. The question is, when designing a new liquid chromatography system, should you create this detector technology in-house or partner with an external company that specializes in designing and manufacturing instrument or application optimised liquid chromatography detectors?
Read interview in full.
March 23rd 2023
Flowmeter FAQ 4
Q: Testa Analytical flowmeters are small devices which fit neatly in the palm of a hand. However, in which orientation (vertical or horizontal) is it best to operate the device?
A: The best operating position is undoubtedly upright with the display readable. This is the "designed"”" orientation. However, TESTA flowmeters will work in any orientation with minimal effect on the measured flow rate. As such, we recommend that you choose an orientation, and keep it constant in order to obtain reproducible results.
Learn more.
February 23rd 2023
Flowmeter FAQ 3
Q: I am using a TESTA flowmeter to optimise liquid reagent delivery by my flow chemistry system. I detect huge difference between the flow rate I set on the system pump and the measured value obtained by the flowmeter. Is my flowmeter defective?
A: No, the flowmeter is doing exactly what it was designed for. Most flow chemistry pumps are optimized around a single flowrate value and for a particular solvent. If you deviate far from this optimization point and use a different solvent, this can result in a notable deviation between the real flow rate and the set value. However, this is exactly why a flowmeter is an absolute necessity for improving the reproducibility and yield from your chemical reactions. Our chemistry flowmeter supplies the real current flow rate of liquid reagents being added and shows also what fluctuations occur at a particular setting. Knowledge of this will allow you to optimise your flow chemistry reaction accordingly and even to select pumps better suited for your application.
Learn more.
December 15th 2022
Removing inter-detector delay improves triple detection GPC/SEC.
Triple detection GPC/SEC is a tried and trusted technique for determining structural information about investigated samples, and to do this without the need of any calibration or reference material. Often, structure information can be expressed in terms of the Mark-Howink coefficients Alpha and K, which allow rapid comparison of structural properties of materials without the need for branching calculations which tend to be tedious and can be prone to error. However, the exactness of any structure related evaluation puts high demands on the accuracy of the measurements and especially on the set-up of GPC/SEC detectors to minimize inter-detector volume delay. Our COMBO #DRIViscometerdetector, with its unique zero delay design, is the perfect match for any MALS detector creating a triple detection GPC/SEC system of unmatched performance.
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December 7th 2022
Continuous monitoring vs scheduled validation of HPLC Pump flow.
To ensure the quality and reliability of your HPLC system data it is important to validate the performance of your HPLC Pump on a regular basis. Some labs choose to do this using scheduled pump flow measurements maybe once a month. However, this type of intermittent performance validation offers only a single data point, and many separations might be run between validations before an error condition is revealed. Continuous monitoring, which is very easily realized using a TESTA Liquid Chromatography Flowmeter, allows continuous determination of flow therefore providing validation of each and every separation run with your HPLC system. This non-invasive device is proven to offer a highly reliable quality assessment of real time liquid flowdata from any HPLC, UHPLC, Ion-Chromatography or GPC/SEC system.
Learn more.
October 12th 2022
How to improve your polymer branching determination
Determination of polymer branching with GPC/SEC is often a challenging task. The requirements regarding accuracy and precision of measured data are more demanding than those for simple molecular weight determination. This challenge places specific requirements on your choice of the required GPC/SEC detectors - DRI, MALS, and viscometer. The typical connection of these three detectors in series leads to an improvement in branching determination results. However, as the delay volume between detectors cannot be optimized, this limits the quality of achievable results. Through development of a combined DRI Viscometer, the HK Combo in which the DRI cell is integral component of the viscometer bridge, TESTA has overcome most of the described problems through its unique “Zero-Delay” design. Used in combination with a MALS, this elegant solution leads to enhanced sensitivity in the lower molecular weight range and to much higher #reliabilityofresults.
Learn more about the HK Combo
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