Carbonates on Psi

Drafty Psi Method

Weigh your samples

1. Find clean vials and a tray - in drawer under polly prepline
2. Find the Psi standards - desiccator
3. Clumped - Ideally you will have one complete set of standards analyzed each day (8 standards in total - ETH1, ETH2, ETH3, ETH4, IAEAC1, IAEAC2, Merck, GU1). Mix them up and randomize their order. This is two sets of standards per tray of 50 vials.
4. Bulk - use ETH4, Coral, and IAEAC1
li>
5. Clumped - Weigh 1000 µg (± 10 µg) of pure carbonate
6. Bulk - Weigh 100 µg (± 10 µg)
7. Clumped - You will also need to run at least two equilibrated gases.

Go Start Psi

1. Check if the previous run has finished or if Psi has crashed
2. Pull lines out of liquid nitrogen dewar and drape off of the floor
3. run reset everything - Analysis > Sequence > Edit > psi_reset_everything.seq, the click Run
4. if Psi Crashed, evacuate and bake traps - Analysis > Sequence > Edit > psi_bake_all_traps.seq, the click Run
5. thaw and dry out liquid nitrogen lines - Analysis > Sequence > Edit > psi_dry_out_liquid_nitrogen_lines.seq, the click Run
6. Create a batch file:
   • Open C:/Nu Stable/Batches/_Clumped_Batch_Template_v23.TXT
   • save as with today's date and descriptive name (yymmdd_YourProject.txt) into the same directory the template was in
   • enter sample and standard information into batch file template and save
   • TYPE THE STANDARDS IN EXACTLY AS TYPED ABOVE
   • Enter each replicate of a given sample identically throughout your session and between sessions if appropriate. For example, "sample_1" should be entered as "sample_1" every time it is analyzed. Do not enter "sample_1_rep1", "sample_1_rep2", etc. You will be able to differentiate individual replicates using a unique identifier provided by the instrument as well as the date and time of analysis. The purpose of entering all replicates identically is to leverage Daeron's (2021) error propagation python code called D47crunch, which we employ.
   • Some prefer to use a text editor while others prefer to use the Nu Stable software interface to create / edit the batch files
7. run reset everything again - Analysis > Sequence > Edit > psi_reset_everything.seq, the click Run
8. fill out daily log
9. fill up the liquid nitrogen dewar
10. place liquid nitrogen lines into the dewar and wrap the fleece cozy around the lines and top of dewar
11. start - Analysis > Batch > Setup-Full > Open > select your batch file > Run

Do some dishes

Data

• On the Psi computer, double click on "C:\psi\rclone_psi_results.bat". This will transfer all the new data to the data server.
• Sitting at one of the zax computers, open R or Rstudio. Type "source('psi.R')" and hit enter.
• Enter the session your samples are in and then work your way through each sample, checking the data presented to you, looking over the figures, and entering any comments you wish to enter about particular samples.
• Once all of the new samples have been initially and individually screened, you are shown a series of figures comprised of all data in the session. Look through each figure and decide if all the data you are looking at are suitable for calibration. If not, open the log file from "S:/Data/projects/psi/Results/[YOUR_SESSION]/psi_[YOUR_SESSION]__samplelog.csv", find the analysis that you wish to exclude, enter a zero in the flag column, provide a comment as to why you are flagging it as zero in the comment column, save, and close.
• Open python and type "py psi_calibrate.py" and hit enter. Enter your session. If more than one *_samplelog.csv" file exists in your session folder, you will be asked to choose one.
• Look over the data and figures presented to you. If you found outliers you wish to exclude or sample IDs that are not entered correctly, repeat the above few steps and rerun psi_calibrate.py

Signature

I have read and understood the present SOP and, before starting work outlined in the present SOP, I will complete all required training.