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A
Summary of Group Responsibilities
Since most research groups operate under a commune-type relationship, it is necessary for each person in the laboratory to perform their respective duties. The following section attempts to outline the different types of responsibilities involved with maintaining a smooth running research group. Also included within this section is some information detailing what is involved with each of these responsibilities. It is worthwhile to attempt to gain experience with each of these chores so that you may become proficient, as you may be called upon to perform similar tasks in future employment (assuming that chemistry is in your future!). 1) Maintaining the Anhydrous Solvent Stills If your research lab is involved with
the handling of air and moisture sensitive reagents, it is necessary to
maintain anhydrous solvents in order to run your reactions. Thus,
ensuring
a low water content in the solvents employed is absolutely necessary.
The
following are some instructions for handling the solvent stills. Note
that
all solvents are distilled under a stream of dry nitrogen or argon to
ensure
the anhydrous nature of the solvent, as well as to eliminate the
exposure
of these solvents to air (a necessity for performing air sensitive
chemistry).
Argon gas is somewhat superior to nitrogen in that it is heavier and is
less prone to displacement by air.
Quenching
of a still is typically accomplished by cooling the pot of the
distillation
apparatus to 0 °C and slowly adding t-butyl- or
isopropyl
alcohol to the mixture with vigorous stirring, although we have been
experimenting with quenches at higher temperatures. Students
must be checked out by me in
order to be allowed to perform quenches; if
the process is done incorrectly, fires and/or explosions can occur.
This type
of still is quenched as above, except that 95% ethanol is used as the
acid.
Once again, I must check you out before you can do it on your own (but
not alone, of course!).
The solvents listed above are among
the ones more commonly in organic research. If you require other
anhydrous
solvents, two excellent sources of methods for the purification of
chemicals
is shown below.
**Benzene is toxic and carcinogenic; it should be used only when absolutely necessary and only after checking with me first.  2) Group Supplies This important job is to ensure that the group has a continuous supply of single-use items which researchers use daily; if we run out, things can come to a screeching halt! Some things we get from the stockroom; others we order. These items include acetone for cleaning glassware, anhydrous ethyl ether, paper towels, bulk solvents, disposable pipettes and small test tubes, concentrated acids, certain inorganic reagents, Kimwipes7, TLC plates, and the like. Although there is a place on the board
for people to write items that we need, part of this responsibility
entails
just being vigilant. It's nearly always possible, and an excellent
idea,
to have an item or two "in stock" in the lab, so that if we run out of
something on a weekend, we won't run out (get it?). This would be
particularly
true for solvents and acids.
 3)
Vacuum Pumps, Manifold, Rack, and Lines This job is one that, if not done
conscientiously,
will have other group members screaming! The area around the vacuum
rack
must , as well as periodically cleaning the glassware associated with
the
line and occasionally re-greasing the ground glass joints of the vacuum
line glassware. In addition, it is necessary to periodically drain the
pump oil from these mechanisms, rinsing the inner chamber with organic
solvent (usually with acetone or dichloromethane), and refilling the
chamber
with fresh pump oil. This needs to be done once every three months to
ensure
a long life of each vacuum pump. It is suggested that a maintenance log
is kept for each individual vacuum pump describing problems with the
pump,
routine maintenance, oil changes, and the last measured operating
pressure
for each pump. If extended maintenance is required for a pump, the
device
in question should be taken down to the stockroom along with a tag
explaining
whose pump it is and what the problem is with the pump. A more detailed
description for changing the pump oil is included in a later section of
this manual.
Ensure that there are ample
quantities
of the most commonly employed solutions used during the aqueous
work-ups
of organic reactions. The common aqueous solutions employed our
research
lab are the following (all are saturated solutions unless otherwise
specified):
To prepare saturated wash solutions, continue to add the inorganic salts to one gallon of distilled water until no more salt dissolves into solution and then add an additional quantity of the salt so that there is a layer of the salt about 1" deep at the bottom of the bottle. Doing this ensures that the wash solution will remain saturated. A 5% aqueous solution of sodium hydroxide is prepared by dissolving 5 g of NaOH for every 100 mL of distilled water employed in preparing the solution. These are best stored in plastic bottles as highly alkaline (basic) solutions tend to etch glass upon standing for long periods of time.
A 1.5 M solution of hydrochloric acid
may be prepared by diluting concentrated (12 M) HCl with distilled
water.
The ratio for such solutions is 125 mL of concentrated HCl and 875 mL
of
distilled water. This will prepare 1 L of the desired solution.
We inherited a nearly-new gas chromatograph
this year; Bob Graham did the initial R&D work on getting it up and
running. This job entails keeping an eye on our new tool, making sure
that
the hydrogen tank isn't empty, keeping the area around the GC clean and
orderly, and be prepared to check out new students on its proper use
and
maintenance. A GC of a standard mixture should be run every week or so,
to confirm that it's operating properly, that we get baseline
separation
between peaks, that the computer interface is solid, and that the
integration
is functioning properly.
It
is this person's responsibility
to see to it that the balance area is being maintained in a clean
fashion
and to ensure that the balance is kept in working order. Should
problems
arise with the balance, it should be called in to either the stockroom
or to Mr. Ramsey in the electronic shop down stairs. In addition to
this,
the person with this duty should also see to it that the refrigerator
and
other electronic or mechanical devices are in good working order. Also
included in these items are the heating mantles, the hoods, light
fixtures,
the variable voltage transformers, the hoods, the rotary evaporator
(Rotovap),
and hot plates. Many of these items may be repaired by Terry Ramsey in
the electronic shop on the first floor.
It
is this person's responsibility
to act as a liaison between the group and the chemical companies who
supply
the reagents and equipment employed within the lab. They are assigned
to
compile a list of chemicals required by the group, finding optimum
prices
for these chemicals, and ensuring a speedy delivery of these chemicals.
In addition, they are responsible for checking with the chemical
inventory
person, to ensure we do not already possess this chemical, and with the
research adviser for approval of the chemical order.
8) Chemical Inventory/Receiving The
person given this responsibility
is entrusted to ensure that records are maintained for each chemical on
hand. Ideally, these records should include the identity of the
chemical,
the quantity on hand, the date received and opened, the supplier of the
chemical, and the location of this chemical within the research lab.
This
individual should attempt to make special note of any important storage
requirements, and should file the necessary MSDS (Material Safety Data
Sheets) of these chemicals for easy access within the group.
There are several reagents that are
used fairly universally in our group, and this person's job is to be
sure
that we don't run out of distilled, pure reagents, stored in serum
bottles
to be used for syringe transfer. The reagents are, usually, the
following:
Work
with HB to maintain the group
web site, add links/data as requested by other group members or because
you think it'd be a good idea, come up with ways/ideas to make the site
more useful to group members and more attractive to outside viewers.
Knowledge
of HTML not required, but it sure doesn't hurt.
The Waste Manager must ensure that
log records are being maintained for each waste bottle and must act as
a liaison between the stockroom and the research group for getting a
timely
schedule for waste collection. Forms for these waste bottles may be
obtained
from the stockroom and ideal containers for waste storage are 1 gallon
glass bottles which are coated with a shatter resistant layer of
polymer
to prevent leakage if a breakage occurs. These bottles must also be
properly
labeled to ensure easy identification and content of these bottles.
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