Tag: HPLC

How Long to Equlibrate an HPLC Column?

This is a question commonly asked by HPLC analysts, particularly those relatively new to the technique. The range of currently available column dimensions means that a ‘one size fits all’ approach is not appropriate. The amount of mobile phase which should be flushed through a column before it is ready to use is usually expressed […]

HPLC Mobile Phase Expiry Dates

Question: What is the typical (the industrial ‘norm’) for the expiration date of mobile phases for HPLC, i.e. with buffer and without buffer. Also, what should you do (e.g., measure the pH or run and verify the retention time) if you need to extend the expiration date in extenuating circumstance e.g. shortage of acetonitrile or […]

Replicates in Analytical Methods: When and How Many?

Do you prepare your samples/standards in duplicate without really thinking about it? If challenged on why, would your answer be something like, “it’s good practice, isn’t it?” The use of replicates in analytical procedures is commonplace but it is important to understand why you are doing it and also what the results are telling you. […]