2
instrumentation was calibrated, how experimental controls were set up, any sampling and
analysis protocols that were used, calculations that are not routine, etc. The amount of detail
given should not be more than is necessary for the reader to repeat what you have done in the
general sense. For instance, if you are describing how calibration solutions were made, it is
appropriate to say, “A range of Ca
2+
calibration solutions from 1.00µM to 10.0µM were prepared
using volumetric glassware by serially diluting the 5.00mM Ca
2+
stock solution with deionized
water.” (We assume here that the 5.00mM Ca
2+
stock solution has already been discussed.) This
amount of detail will allow anyone familiar with wet chemistry to make calibration solutions in
the proper range. It would not be appropriate to say, “To make a 10µM Ca
2+
calibration
standard, 2.00mL of the 5.00mM Ca
2+
stock solution was added to a 1000mL volumetric flask
using a 2.000 mL volumetric pipet, and then the volumetric flask was diluted to the mark with
deionized water.” This statement is wordy and unnecessary. However, if you are discussing a
procedure that is new, extremely uncommon, or very sensitive to small changes in the procedure
that may alter the outcome of the experiment, then this sort of detail may be appropriate. If some
parameter was changed half-way through the experiment (and data is used from both before and
after changing the parameter), then it should be mentioned in the experiment section. Why the
parameter was changed should appear in the discussion section (a brief comment on why it was
changed could be included in the experiment section to avoid confusion). None of your actual
data or results should be presented in the experimental section.
Figures may be used in the experimental section if they show how an instrument was set-
up or to show visually how an experiment was carried out. A table may be used to demonstrate a
sampling protocol in a better way than could be explained in the text. In general, figures and
tables should always be used sparingly, and only if they result in a better presentation of
information than can be accomplished in the text. Never put a figure or table in your paper
unless you refer to it in the text, and specifically discuss the contents of the figure or table in the
text. If one of your figures is used to show an equation, use an equation editor to properly
present this.
Most of the time, the experimental section will be written in the past tense. Any time you
discuss something that was done in your experiment it should be in the past tense. However, if
you are writing about something in the general sense, then the present tense should be used. For
example, “Mass 67
+
was used to monitor isoprene since it is the most prevalent mass produced
in the electron impact ionization of isoprene.” The first part of the sentence is in the past tense
since it refers to the experiment, the second part of the sentence is in the present tense, since it is
a general property of electron impact ionization.
Results/Data
The results/data section presents your data to the reader, but does not present an analysis
of that data. Since this is sometimes difficult to do, it is common to combine the results section
with the discussion section. Only show results that are pertinent to your experiment. If you
made a mistake during the experiment, do not show the data from the mistake. Only show bad
data if that data was used to direct the next step of the experiment. This would be common if
your experiment involved method or instrument development. Do not show the same type of
data more than once unless there is a good reason to do so. If you are analyzing ten samples with
various concentrations of phenols by chromatography there is no reason to present more than one
of the chromatograms; in general, they all look the same. A graph of concentration versus
sample number, or time, or whatever is appropriate, would be more useful to the reader. Be sure