Liquid Chromatography

Shimadzu has launched its i-Series Plus integrated HPLC system that covers conventional to ultra-fast LC analysis. The launch coincides with the company's 50th anniversary of its presence in Europe.

Shifting retention times within a sample batch can be a real source of headaches in the routine HPLC laboratory. Previously we talked about the kind of retention drift experienced by some HPLC methods for the first few injections. This often is...

How many of you have experienced this? You think you’ve fully equilibrated the HPLC column by running mobile phase through it for 30 min, but for the first 3 or 4 injections, the retention times drift a little, finally settling down after half a...

In this technical article you will learn about which properties are necessary when choosing a compound to use as an internal standard. 

In this technical article you'll learn how an internal standard is used in quantitative analysis.

Agilent Technologies has produced an application note describing a combined approach to analytical method development and method transfer by direct emulation of different target HPLC systems. The proposed workflow presents a general approach to...

It is easy to take knowledge for granted, especially when you’ve been involved in a field for a long time, as I have with HPLC. One of those areas is about how to protect the column. In the training courses we teach, Tom Jupille and I jokingly...

In an earlier blog, we looked at the processes of sample filtration or centrifugation as a means of reducing or eliminating particulate matter from the injected sample. As I mentioned, I prefer centrifugation, because it is easy, inexpensive and...

In previous blog posts we've talked about various aspects of buffers. We saw that some buffers were better than others and that there were certain buffer-preparation practices that should be avoided. This prompted one reader (I.M.) to remind me of...

Sometimes I don’t know whether to be amused or dismayed when I am presented with an HPLC method. Whether it is a method question from one of the readers or a paper to review for the 'Journal of Chromatography', it is a bit surprising to me how often...

My first “real” job was working for Technicon Instruments Corp. in Tarrytown, New York, USA. My boss was Lloyd Snyder, who was to become a close friend and who has been my business partner for almost 26 years. Little did I know what my future had in...

Save 50% on the cost of your LC-MS! Now that I have your attention, perhaps I shouldn’t make such a grand claim – maybe only 40%. Of course I’m talking about operating costs, not the purchase price, but if it means that you can do the work of two...

Q: I have observed peak splitting in my chromatograms when I inject the sample in tetrahydrofuran (THF) as the injection solvent, but I don’t see any problems when acetonitrile (ACN) is used. I am using a C18 column with a mobile phase of ACN/buffer...

Q: What buffer should I use when I want to optimize the pH of the mobile phase? I normally use phosphate buffer, but I heard that phosphate may not always work. How can this be? I thought that phosphate was a great buffer for reversed-phase HPLC....

In an earlier blog article, we looked at the effect of trifluoroacetic acid (TFA) concentration on retention when the mobile-phase pH was controlled by adjustment with TFA. Much of the time, especially at low pH, you can get consistent results by...