Helpful Pointers for Successful Synthetic Chemistry, Lab Cleanliness

The tips below and many more are covered in greater detail in my book Cationic Polymerization Resource: Volume 1, Non-living Polymerizations of Olefins.  That work is finally nearing completion and once in print I will post a blog article about it.  Please note, many of these recommendations also apply to other segments of chemistry (e.g., analytical).

Having a Clean Work Environment

Cleanliness is probably one of the most overlooked factors that success or failure may hinge on in context to synthetic chemistry.  The following should be clean:

  1. All work surfaces {e.g., benchtop, chemical hood (walls, apron), metal scaffolding, and stirrer hotplates}.  This can be accomplished using a variety of methods like scrubbing with an abrasive pad and spray cleaner, solvents, etc.  Care must be taken if solvents are to be used as they can potentially damage the surface being cleaned in addition to causing bodily harm to the operator.  Unfortunately some residues will only be removed by using certain solvents as they are impervious to less aggressive cleaning solutions commonly used in the household.  If left unclean these surfaces can become sources of contamination even if they are not in direct contact with the system being studied as contaminates can enter by falling into it.  Furthermore, if you happen to have a spill and must recover the spilled material a clean work surface will reduce the likelihood of the reagent in question from being irreparably contaminated.  Sacrificial coverings can be used in certain instances (e.g., aluminum foil, freezer paper); however, most have poor chemical resistance and are not recommended.
  2. Glassware and all items that come into contact with reagents.  This author recommends the use of base and acid cleaning baths for glassware, metal spatulas, and other items that are resistant to this method of cleaning whenever possible.  Additional rinsing with deionized water is a good step when very minor contaminates might pose a problem.  Sometimes more aggressive cleaning solutions such as aqua regia or piranha solution might be required.  All of these methods present a risk to the chemist in that the solutions can easily cause bodily harm and thus they must be handled with proper technique and appropriate personal protective equipment.  Additionally, glass base baths can damage to certain items (e.g., glass filtration frits, NMR tubes, etc.) if they are immersed in the bath for prolonged periods of time.
  3. Syringes, needles, rubber turn over septa, PTFE stopcocks, and other delicate items.  Some items should only be cleaned with soap and water and/or with solvents.  They can be grouped into small glass or plastic containers fitted with a secure lid and soaked if desired.  This author has found that simply forcing a stream of solvent through and/or over the item in question typically will remove the bulk of chemical residue.  Careful use of ultrasonic cleaning baths provide another option.  This author does not have extensive experience using ultrasonic cleaning baths as many of the labs he worked in as a graduate student did not possess this item.  It would seem feasible that certain items needing to be cleaned could be placed within a small bottle or vial containing solvent, the container then being sealed, and finally immersed into the water bath of the ultrasonic cleaner.  Care should be exercised since pressure could build within the containing holding the solvent and cause it to rupture.
  4. Nonconsumable items with metal surfaces (e.g., spatulas) can be polished with mild abrasive pads/rags.  This generally will remove any oxides or residues that solvents cannot remove.  In certain instances the use of such abrasives are useful for cleaning porcelain and glass apparatuses but care must be taken to choose an abrasive that will not mar the surface of the item being cleaned.