Analytical Laboratory What Not To Do – Post 1

This pharmaceutical scientist has just returned from a week in Europe.  Returning to work on a Friday has spurred some less topical laboratory ranting.

Over my 20 years of lab experience (wow…), I have seen many “interesting” techniques in the lab.  Take this as the start of a list of What Not to Do in a Lab posts that will be posted occasionally   Let me also point out that these were observed in people who have degrees ranging from high school diploma to PhD.


Preparing mobile phase in a graduated cylinder:

A friend of mine observed a PhD chemist prepare a mixture of acetonitrile and water in a graduated cylinder.  I am not going to assume that all my readers are chemists, so I will explain the problem.

When two solvents combine, many times you get an endothermic (gets cold to the touch) or exothermic (gets hot to the touch) interaction.  When liquids are cold, they shrink.  When they are hot, they expand.

So, you measure liquids with a graduated cylinder because you want to be accurate in the volumes.  If you measure them together and they get hot or cold, you have just changed the volumes!  Maybe the final volumes are not that important to your work, but this is still very sloppy labwork.


Crazy and Lucky thing that happened to me a few weeks ago in the lab:

Our HPLCs use many liters of flammable liquids and therefore leak sensors are built into the instrument to stop and shut down if a leak is detected.  This usually works beautifully.

Last night, I had an HPLC column leak.  The solvent ran along the bottom of the column compartment, out the side, and dripped onto a fortuitously placed box of lab wipes.  This box happened to be overhanging the end of the bench overtop the solvent waste secondary container.  All the leaking solvent soaked into the box of labwipes and dripped from the corner of the box into the secondary container.

From a spill of ~1.5L, I had approximately 1 mL to clean off the bench and none on the floor!   A lucky chemist!


  1. I can imaging this list of “what not to do in a lab” could get huge. When we visit other labs that have a range of experienced scientists many times the more experienced scientists are lax in procedures compared to post doc and grad students. Not sure why this seem to be.

    Anybody have any thoughts about why this is?

    Joseph Mas
    Phoslab Environmental Services

  2. Lisa Crandall

    Joseph, thanks for the comment!
    In our experience, we’ve seen lax procedures all over the board that don’t seem to correlate with education or age. I think it all boils down to who trained you and how receptive you are to cementing good habits into your daily lab practice.


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