Instrument Chemistry

Paper, Order, or Assignment Requirements


1. HPLC columns

Read this link

Click to access 036-ColumnComparisonGuide.pdf


Note that these are the same document but I could not download the first one when I tried again and the second I could only read online.
It compares HPLC column performance. Using it and other sources, answer the following questions.

A. Choose two columns of nearly equal hydrophobicity from Fig 4 and explain why the separations and retention times differ. Although some information is available in Fig. 3, you might need to look at the manufacturers’ specifications.
B. Fig. 12 gives column efficiency in plates/meter for the pyridine peak. Why are the first three chromatograms in the top row so different?
C. Fig. 15 shows a comparison for a mixture of amines. Why are the chromatograms in the third vertical column so different for these C-18 columns?

2. Forensic drug testing

Click to access 171.full.pdf

Explain the difference in these two methods above in terms of sample collection, sample preparation, chromatographic conditions, interface, detector, sensitivity, methodology, automation, etc.