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CHEM 370

HPLC Data Processing

Table of Contents
  1. Export & Organize Your Data
  2. Import Your Data
  3. Integrate the Peaks
  4. Create a Standard Curve
  5. Validate Your Results
  6. Determine the Concentration of Your Samples
  7. Save & Turn In Your Work

Use the following link to download the notebook template for this lab:

https://raw.githubusercontent.com/chem370/chem370.github.io/master/docs/project/hplc/hplc-notebook-template.jl

The following video walks you through the data processing portion of this lab.

Having trouble viewing this video? Click here to view it on Panopto instead.

You should turn a your complete lab notebook as an .html and .jl file functioning with no errors and your CSV file.

Export & Organize Your Data

  1. Manually export your chromatograms as CSV files using Agilent ChemStation on the HPLC Computer:

    1. Navigate to the data processing pane (lower left side of the window).
    2. Find your run in the data broswer on the left side of the screen and double click to open it.
    3. Double click the line for your first chromatogram in the sequence (top middle section of software) so that the text turns blue.
    4. Right click on that same chromatogram and choose Export > CSV then make sure Signal is selected in the resulting window. Follow the prompts to export your data, making sure to give each sample an appropriate name.
    5. Repeat these steps for every sample you ran.

  2. Place all your CSV files in the same folder as your lab notebook.

Make sure you don't have any extra CSV files in this folder. Every CSV in this folder will get imported into Julia when you read the data.

Import Your Data

  1. Use the custom importHPLC() function to import all of your data at once. This function takes no arguments (just make sure your notebook and CSV files are in the same folder.)
  2. You may wish to plot the chromatograms for inspection before moving further. One way to quickly do this is:
 @df hplc_data plot(:Time, cols(2:ncol(hplc_data)))

Integrate the Peaks

  1. Use your standards to determine the retention time for acetaminophen.
  2. Use the fitPeak() function to to integrate the peaks at the desired retention time.
  3. Use the plotPeak() function to visualize the results of the peak integrations.
Don't disregard the peaks that aren't acetaminophen. They contain valuable information that you should discuss.

Create a Standard Curve

  1. Use Julia to fit and plot a standard curve. (See Lab 2 if you need a review.)

Validate Your Results

  1. Determine the concentration of the QC.
  2. Determine the percent difference from the expected value.
  3. Determine your LOD and LOQ. For the standard deviation of your blank, use the standard deviation of the entire blank chromatogram.

Determine the Concentration of Your Samples

  1. Determine the concentration of your samples. Remember to factor in all dilutions. (See Lab 2 if you need a review.)
  2. Use the confidence intervals or a t-test (whichever you prefer) to determine whether the concentration is significantly than the expected value. (See Useful Information > Comparing Means for more information.)

Save & Turn In Your Work

  1. Save your work as a .jl (Julia) file and .html (static HTML).
  2. Attach your .jl, .html, and .csv files to the MS Teams assignment for this lab when turning it in.