Johanna Suhonen and Oscar Cavazos

Ampulator

The ampule sealer was not used. “Free” ampules from lab drawers were relocated to the store room.

Balances

Cahn and Mettler balances were in light use, and both systems worked well. A spare Mettler is supposed to be in the shipment for X403.

Carver Presses

Carver presses were not used. The hydraulic fluid levels in Autopaks were checked and topped up where necessary. The presses were tested, and they all are in good working order.  

Cary Spectrophotometer

The spectrophotometer was not used.

Coulometer

The coulometer was not used.

Elemental Analyzer

The X399 hard rock samples from College Station were analyzed for carbon and hydrogen on the CHNS as per a request from Margot Godard (X399).

The magnesium perchlorate trap was emptied for the purpose of analyzing for hydrogen, and the trap is currently empty.

Freeze-Dryer

The freeze-dryer was not used. Oil mist filter was drained and pump oil level was checked. The freeze-dryer was tested. It is working well.

Fume Hoods

There were no issues with the fume hoods.

Gas Lines/Manifold

There were no issues with gas lines/manifold.

GC: NGA1/NGA2/GC2

NGA1 was used for the final phase of the helium conservation experiment. First, generator nitrogen was connected to NGA1 FID makeup inlet. Similar cyclic baseline abnormalities appeared as were observed back in 2020 when the first generator nitrogen tests were performed. Agilent recommended trying to purify the generator nitrogen with a nitrogen purifier trap. A trap was installed, and it did indeed make a significant difference in the baseline. It immediately cleaned out the “bumps”. It did take two days for the baseline to stabilize around 115 pA with the purified generator nitrogen as makeup. The STD B chromatogram came out as it does with helium as makeup gas. The only minor difference seen in STD B (He vs. N2) was an approximately 1.5 min long bump in the baseline around 3 minutes into a run (lab air was also run several times, and the same bump in the same place was observed). This bump is not present when helium is used as makeup. No explanation was found for the bump, and it remained for the duration of the experiment. It did not affect the integration of the peaks. At the end of the experiment the instrument was returned to its original settings with helium as makeup gas. STD B was run to confirm normal operation. Conclusion: Generator nitrogen can be cleaned up enough with a nitrogen purifier trap to be used as makeup gas.

Complete report with screen captures can be viewed on Confluence:

http://confluence.ship.iodp.tamu.edu:8090/display/LN/GC+NGA1+Agilent+7890A

NGA2 was not used.

GC2 was not used.

According to the LO all GC and SRA calibration standards can stay in the gas standard cabinet as is for possible future expeditions. They would not be shipped back, and this way they do not have to be discarded.

Hydrogen Generators

No issues with the hydrogen generators.

IC

Fluids were circulated through the IC weekly. No issues were experienced.  

ICP

27 hard rock samples from X399 sampling party were run on the ICP. The instrument worked well. The data were sent to Vinny, and they have been uploaded into the shore database.

Microbiology

Expedition 402T had no microbiologists. The incubators were defrosted and turned off.

Salinity

The refractometers were not used.

SRA

The SRA was not used. 

Pipettes

Pipettes worked well. No issues.

Titrations

ALKALINITY

The alkalinity titrator was not used. 

CHLORINITY

The chlorinity titrator was not used.

Water System

The water system was in moderate use and worked well. It might get to remain onboard for possible future expeditions.

The pre-filter under the counter was replaced.

AMI Nitrogen Gas O2 Sensor

The O₂ sensor worked well. There were no significant fluctuations in the generator nitrogen O₂ level.  The level mostly stayed around 4 ppm.

Misc

The furnace was not used.