Welcome to the Biotage Flash Purification Blogs.

    How do I remove an annoying MS TIC background?

    April 10, 2020 at 2:52 PM / by Bob Bickler posted in Chromatography Fundamentals, Troubleshooting and Optimization, Sfär, Detector, Normal Phase, V-10, Isolera

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    Have you ever run flash column chromatography with mass detection (Flash-MS) and observed the total ion current or TIC increase during the purification only to find that there was no discernible compound contributing to the effect?

    In this post I discuss how I came across this issue and the solution I found to work.

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    When should I choose APCI or ESI for my flash column chromatography?

    February 11, 2020 at 3:16 PM / by Bob Bickler posted in Detector, Isolera

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    Mass spectrometers today are typically available with either Electrospray Ionization (ESI) or APCI (Atmospheric Pressure Chemical Ionization) sources.  That’s really nice but, how do you know which source will work best when purifying your sample?

    In this post I attempt to provide some guidance to selecting the ionization source best suited to your sample types.

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    Flash system UV detectors – similarities and differences

    February 4, 2020 at 10:28 AM / by Bob Bickler posted in Chromatography Fundamentals, Selekt, Detector

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    Flash purification is a preparative liquid chromatography technique. As such, it incorporates the same types of components as preparative high-pressure liquid chromatography (pHPLC) – pump, gradient mixer, column, UV detector, and fraction collector. Though all flash chromatography systems are purpose-built and essentially work the same, the one area of difference is in the UV detector design and operation.

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    So, how does an ELSD work?

    January 7, 2020 at 9:06 PM / by Bob Bickler posted in Detector

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    Evaporative Light-Scattering Detection, or ELSD for short, is a technology used with liquid chromatography to see UV-transparent (and UV-absorbing) compounds. In a previous post I talked about some applications where ELSD is not only useful, but required.

    In this post, I will explain how an ELSD is configured and functions.

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    So, which detector should I use for flash column chromatography?

    January 3, 2020 at 3:38 PM / by Bob Bickler posted in Reversed-phase, Detector, Normal Phase

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    In my role as senior technical specialist at Biotage I am often asked about compound detection options. For most flash chromatography methods, UV is the default detection tool since many compounds do absorb some UV light.

    Diode array UV detectors provide chemists choices in wavelength selection providing the ability to widen or narrow the wavelength range needed to detect specific compounds and enhance their sensitivity.

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    Detecting the undetectable in flash column chromatography using wavelength focusing

    October 2, 2019 at 5:52 PM / by Bob Bickler posted in Chromatography Fundamentals, Selekt, Detector, Isolera

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    Sometimes it feels as if organic chemistry and chromatography are a mixture of art and science.  Maybe its because of the necessary creativity needed to address the variety of challenges that we face almost daily.  Frankly, its what I find most interesting about this world.

    One of the bigger challenges facing chemists is the ability to detect and collect compounds with little or no UV absorption during flash purification.  In this post I will talk about a technique that I have found to be quite useful when trying to purify mixtures containing one or more poor absorbers.

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    Are there benefits to collecting flash chromatography fractions based on multiple UV wavelengths?

    January 8, 2019 at 7:29 PM / by Bob Bickler posted in Chromatography Fundamentals, Selekt, Detector

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    UV detection and fractionation is ubiquitous in flash chromatography. It is the default methodology used to detect and collect eluting compounds. Today’s flash chromatography systems offer UV-triggered fractionation on one, two, or a range of wavelengths in order to either increase fractionation specificity, yield, or increase sensitivity.

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    The value of in-line mass detection with flash column chromatography

    December 11, 2018 at 7:56 PM / by Bob Bickler posted in Reversed-phase, Sfär, Detector, Normal Phase, Isolera

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    For many chemists, flash chromatography with UV-triggered fractionation is part of their everyday workflow. Prior to flash chromatography, the reaction mixtures are either analyzed by TLC, analyzed by LC-MS, or both to ensure the targeted product has been synthesized. But, what if the reaction created a lot of by-products? How do you find your product in a sea of impurities? In this post, I will discuss how using a flash purification system with an in-line mass detector will simplify flash purification and isolate the target molecule or molecules. 

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