HPLC Articles

  • The Clog Blog

    Clogging and over pressuring are definitely problematic for Liquid Chromatography columns. Back in 2005 John Dolan’s sage advice to chromatographers to make an LC column last forever was simple, “Never open the box!” As John pointed out, this is not practical and I have to agree. But as an LC column manufacturer I have seen remarks from customers regarding clogging as though it ...


    By Restek Corporation

  • Webinar Recap: “Developing, Testing, and Troubleshooting Chromatography Method Transfer”

    Hi, I’m Tom Wheat, Principal Scientist at Waters, and I recently hosted a webinar entitled, “Developing, Testing and Troubleshooting Chromatography Method Transfer.” Over the course of the webinar, we discussed the transfer of chromatographic methods that occurs at many stages in the development and production of a product. In its simplest form, the method is moved from one ...


    By Waters Corporation

  • Top 16 for 2016 - Restek LC article makes the cut

    If you are an avid chromatographer you likely subscribe to LC/GC magazine or its popular electronic version, E-Separation Solutions. It is definitely the place to go for news and information related to all things Chromatography. Over the years Restek has had many an article published in LC/GC and, full disclosure, we advertise there as well. Who in the business doesn’t? It is the place ...


    By Restek Corporation

  • Fluorophenyl LC Phases- what you should know

     They may be called PFP, PFPP, pentafluorophenyl, fluorophenyl or F5 phases. What they all have in common is the structure shown above (the pentafluorophenyl  group) attached to the silica particles. Most modern phases contain a propyl spacer between the above group and the silica, so that the phase looks something like this: ...


    By Restek Corporation

  • Separation of citral isomers from lemongrass oil

    Reveleris® Prep: Purification with flash chromatography followed by a prep-HPLC isolation of citral isomers Lemongrass is cultivated around the world. It's mainly grown for its oils, which have a number of uses including for vitamin A, perfumes, insect spray, cosmetics, perfumes, food and drinks. Lemongrass is also enjoyed as a tea throughout the world. Lemongrass oil contains several ...


    By BÜCHI Labortechnik AG

  • Why Biphenyl should be your first choice in LC.. A perspective from a “ GC” specialist..

    Being in GC for 38 years it made me wonder why in LC mostly C18 columns are used for developing a method. I never understood this as its against the basic rules for selecting the optimal stationary phase. In LC we see that about 95% of the applications is done using reversed phase materials, especially the C18 type. There are many C18 types available, and they all show a different separation ...


    By Restek Corporation

  • What can I use to filter my mobile phase?

    If you are using mobile phase that contains salts or, generally, any components that are weighed out for its preparation, you will need to filter the solution before using with HPLC or UHPLC. The most common type of filtration is membrane microfiltration. We sell an extensive group of products for this and they are discussed very well in a blog ...


    By Restek Corporation

  • Development of a Cleaning Validation Method for MICRO® A07 Citric Acid Cleaner Using HPLC-CAD

    Abstract A high performance liquid chromatography (HPLC) method with a Corona Charged Aerosol detector for the cleaning validation of MICRO* A07 Citric Acid Cleaner residue has been developed. The pooled average repeatability of 3 replicates at 6 concentration levels expressed as RSD was 1.3 % while the pooled average intermediate precision (intra-day repeatability in 3 days) of 3 replicates ...

  • A brief introduction to DiatoSorb-W

    DiatoSorb-W is a diatomaceous earth material that Restek will sell in bulk and in packed columns, uncoated and coated (with a liquid phase of your choice), which will replace Chromosorb-W packings. For those of you who may not know, the “W” stands for “white”, and is simply the color of the untreated, uncoated material. If your method references USP S1A, or Chromosorb-W/AW ...


    By Restek Corporation

  • Tips to maintain your HPLC & UHPLC systems and columns

    Recently, Ade Kujore (Cecil Instruments), Tracie Brombos (GenTech Scientific) and I were asked by Angelo De Palma, a well-respected writer for Lab Manager magazine, to contribute to an article about maintaining and caring about your laboratory instruments. Here are my tips/best practices for column and HPLC/UHPC/UPLC system maintenance. Maintaining your ...


    By Waters Corporation

  • Glyphosate and AMPA in drinking water

    Carcinogenic or not? The broad-spectrum herbicide glyphosate is used all over the world in agriculture. Alongside farming, the chemical is also used for weed-killing in domestic gardens and in public and private spaces kept free from «vegetal invasion», such as railway tracks. Glyphosate has been used since the 1970s in pesticides and was hitherto thought to be harmless at ...


    By Metrohm AG

  • Comparison of simple ozonation and direct hydrogen peroxide processes in TNT removal from aqueous solution

    Oxidation of 2,4,6-trinitrotoluene (TNT) using simple ozonation and direct hydrogen peroxide was studied. An analytical method based on the HPLC (high performance liquid chromatography) system was used for TNT detection. The influence of parameters such as pH of the solution (3–10), initial TNT concentration (10–100 mg/L), dosage of ozone (0.2–1 g/hr), H2O2/TNT molar ratio (250–1,000), ...


    By IWA Publishing

  • Iridium nanoparticles with high catalytic activity in degradation of acid red-26: an oxidative approach

    Nanocatalysis using metal nanoparticles constitutes one of the emerging technologies for destructive oxidation of organics such as dyes. This paper deals with the degradation of acid red-26 (AR-26), an azo dye by hexacyanoferrate (abbreviated as HCF) (III) using iridium nanoparticles. UV-vis spectroscopy has been employed to obtain the details of the oxidative degradation of the selected dye. ...


    By IWA Publishing

  • Removal of perfluorooctanoic acid (PFOA) in groundwater by nanofiltration membrane

    Perfluorooctanoic acid (PFOA) is very persistent in the environment and resistant to typical degradation processes. PFOA has been widely used in surface-active agents and as an emulsifier in several products and can contaminate groundwater. Groundwater is considered as an important source of water; hence removal of PFOA contamination in groundwater is needed. This study aimed to examine the ...


    By IWA Publishing

  • What is the pressure limit for my LC column?

    This is a question we get in Tech Services fairly often.  Unfortunately, we are not able to provide a published limit for every column that we produce, but here are a few of them that we have specified: For 3 and 5 um fully porous particle ...


    By Restek Corporation

  • Is Microflow LC a Reality or Perception?

    Microflow or nanoflow chromatography has been used mostly in the academic and fundamental research environment in the past for its various advantages over analytical liquid chromatography, but rarely in the industrial settings. This is most likely because many of us believe it is a pain-in-the-neck technique to perform! But is this a reality or just a ...


    By Waters Corporation

  • The Advantages of a Targeted 2D LC Approach

    Webinar Highlights | Focus on the Relevant: The Advantages of a Targeted 2D Chromatography Approach Hi folks, I’m Daniel Root, Senior Product Marketing Manager for Multidimensional LC Systems at Waters. I recently conducted a webinar that addressed multidimensional liquid chromatography – an exceptional tool for the improvement of characterization and separation of ...


    By Waters Corporation

  • Method Scaling in Preparative HPLC: Analytical Method & Preparative Method

    VOC:  “I tried to scale up my analytical HPLC method to prep and it didn’t work.” Andy:  This is one of the most common things we hear from chemists wanting to do preparative chromatography. We also hear the following question pretty often too: VOC:  “I have a good analytical HPLC method, how do I scale it to ...


    By Waters Corporation

  • Impact of pH on Derivatization of Nitrophenol Compounds

    Our goal of evaluating the Normalized French Environmental Method 12673 required testing the method’s ability to derivatize nitrophenols and alkylphenols in addition to the chlorophenols the method was designed for. Unfortunately, nitrophenols proved challenging to derivatize at low concentrations. In an effort to improve the derivatization of nitrophenols, we experimented with the pH of ...


    By Restek Corporation

  • Synthesis of granular nanozeolite NaA from Phragmites australis for removal of total petroleum hydrocarbon

    The purpose of this study was to synthesize granulated nanozeolite NaA particles from Phragmites australis in order to evaluate their efficacy for removal of total petroleum hydrocarbon (TPH). The perennial wetlands grass P. australis was chosen for study because it is one of the most abundant plants found growing around oil refineries. Fourier transform infrared ...


    By IWA Publishing

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