1. You are asked to provide specifications for an instrument that will be purchased for your laboratory.
It will be dedicated to a single purpose so it doesn't need to be flexible. The budget is limited so you
can't afford a GC-MS. What type of column (WCOT, PLOT or packed) and what type of detector (TCD,
FID or NPD) do you recommend for the following purposes? Explain why each choice of column is
better than the two alternatives. Explain why each choice of detector is better than the two
alternatives. Don't just say why your choice would work, explain why the other two choices are
worse. Show that you understand the strengths and weaknesses of these columns and detectors.
a. Analysis of reaction mixtures in an organic synthesis research lab. The target chemicals will
be organic chemicals in fairly high concentration. The target chemicals might have
heteroatoms like chlorine, sulfur and phosphorus or they might not. The samples will come
straight from reaction pots so interferants might be almost anything, from organic polymers
to inorganic catalysts.
b. Trace analysis of organophosphate pesticides in extracts from food products. The extraction
process will have cleaned up the samples before chromatography and concentrated the
target chemicals to ppb concentrations.
c. Analysis of of the toxins $H_2S$, $NH_3$, $CO$, $HCI$ in the flue gas of a reactor. The sample matrix is
air so $O_2$, $N_2$, $Ar$, $CO_2$ and $H_2O$ vapor will also be present. Permissible levels of the target
species (the toxins) are in the low ppm range.