The Effects of Changing Column Inner Diameter on LC-MS Applications-Part 3

Part 3: What is the Best Column ID for You? Hi, and welcome back to the third installation of this article series on the effect of changing column inner diameter (ID) in chromatography.  So far, we have taken the test probe, 17-alpha-OH-progesterone, and run a simple linear gradient on the LC-MS Continue Reading

Can an UHPLC Column Have Too Much Efficiency?

Is 100% aqueous stability and unique polar selectivity not enough to convince you to try Luna Omega? Well, here is another equally-compelling reason Guest Author: Dr. Jeff Layne You Can Never Have Too Much Efficiency! The efficiency of a column is a measurement of the amount of band broadening that Continue Reading

Selectivity for Polar Acids

Guest Author: Dr. Jeff Layne Is super-high efficiency and 100 % aqueous stability not enough to convince you to try Luna® Omega UHPLC Columns? Well then, how about a unique selectivity for polar acidic molecules? Selectivity for Polar Acids is Sweet! Developing robust methods for the analysis of small, polar Continue Reading

The Effects of Changing Column Inner Diameter on LC-MS Applications- Part 2

Part 2: Changing Column Inner Diameter with Constant Flow Rate Guest Author: Dr. Jeff Layne Welcome back to this article series on the effects of changing column inner diameter on LC-MS applications. Well, let’s be fair, we are using LC-MS to illustrate our discussion, but the concepts we cover apply Continue Reading

The Effects of Changing Column Inner Diameter on LC-MS Applications- Part 1

Part 1: Changing Column Inner Diameter While Adjusting Flow Rate Guest Author: Dr. Jeff Layne Welcome everyone! Jeff Layne here, back with another article series, and this time we are returning to our method development roots. In this new series, we are going to address the topic of column inner Continue Reading

Why 100% Aqueous Stability is Important and Fun

Guest Author: Dr. Jeff Layne As the LC Product Manager for Phenomenex, one of the most common requests I get is to explain, in simple and practical terms, the features and benefits of our various LC products. Phenomenex has A LOT of different LC products after being in the business Continue Reading

Jeff Tries Cannabis Part 6: HPLC Method Development

Guest Author: Jeff Layne Well – it seems that we have a little more work to do with cannabis potency testing. I had originally planned to have the last article be the last of this HPLC method development series, however, we had a request to develop a similar separation using Continue Reading

Jeff Tries Cannabis Part 5: HPLC Method Development

Guest author: Jeff Layne Hello again, and welcome back to my cannabinoid method development article series. From the last post, we were finally able to find a few different columns that could successfully resolve all 12 of our target analytes within the pressure limitations imposed by the customer, and within Continue Reading

Jeff Tries Cannabis Part 4: Method Development

Part 4: A New Hope Guest Author: Jeff Layne Hey everyone, and welcome back to the cannabis method development series. So far in our quest to separate the twelve cannabinoids, we have messed around with gradient rates, mobile phase modifiers, and flow rates, yet have only been able to successfully Continue Reading

Jeff Tries Cannabis Part 3: HPLC Method Development

Effect of Flow Rate and Gradient Time in cannabis seperation phenomenex

Part 3: Effect of Flow Rate and Gradient Time Guest author: Jeff Layne Hey everybody, welcome back to my third blog article on cannabis HPLC method development. So far, we have done some preliminary gradient screening to narrow in an effective “gradient window” (75-100% acetonitrile in 10 min) and found Continue Reading