Aaron Mechler & Chang Liu

Ampulator

The Adelphi ampoule sealer was used. No issues to report. Re-marked the lines for the suggested setting on the air and propane knobs to make them easier to see. We replaced the propane bottle during week 5.

Balances

No issues to report for the Cahn & Mettler balances.

Carver Presses/Squeezers

Moderate to light use (lots of IW, but low pressure) and had no leaking. Seems like first expedition for some time without any leaking; it was nice.

At one point, scientists managed to get the titanium plate wedged inside the sleeve with 2 differenct squeezers twice within about 48 hours of each other. Pushed out with force and handed the units off to the ET to smooth out edges and surfaces. They had squeezers parts correctly matched up but they likely weren’t putting much care into how well they were assembling the squeezers. Had to remind them to be more careful about it and make sure parts are seated together correctly.

Cary Spectrophotometer

The Cary was used to analyze ammonium, phosphate, and silica. The visible light bulb was replaced during week 3.

To add to the 382 report mentioning using alkalinity values to determine dilution factor for ammonium; the IC can also be used to determine the dilution as an ammonium peak appears on the IC at high concentrations just to the right and at the base of the sodium peak.

When the peak starts to be detected, as in the first screenshot on the left, it’s about 800-1000 uM ammonium. The second screenshot on the right is at about 6000-7000 uM ammonium.

CHNS

CHNS analyzer was used to measure Carbon and Nitrogen. We originally had some use with the vanadium pentoxide but started noticing some bad accuracy and reproducibility in check standards for nitrogen. After some testing we discovered nitrogen contamination in the vanadium pentoxide. Vendor was contacted and tested their stocks and confirmed the contamination.

Coulometer

At one point, turned gas off after noticing the AgNO3 trap was clogged which resulted in the built up pressure in the system pushing KOH from the first trap back into the flow meter. The flow meter was disassembled and cleaned.

A few weeks later, the ball in the flow meter was stuck at 100. This mislead us when the silver nitrite scrubber needed to be replaced. The flow meter was disassembled and cleaned again and is working well, although the knob for adjustments is super sensitive at the moment.

Part of one of the glassware used for the silver nitrate scrubber was broken off. It was glued back together with epoxy. It needs testing to see if it could still be used with no leaks, otherwise it can be disposed of in broken glass.

Freeze-drier

The Freeze –drier’s menu was uploaded on Confluence.

Occasional warning beeping due to voltage problem. Ship’s voltage, which is supposed to be 208V, was dropping during week 5 and that triggered the alert. We adjusted the range of the voltage alerts (±15 increments) to stop the beeping. Something to keep in mind, the specific style of Freeze-drier in the chemlab should not be run under the voltage of 170V or higher than 290V.

Fume hoods

We spotted a burning hole inside of the Hood #3 at the beginning of the Exp 383. After talking with Brad and Chieh, we don’t think that burning was from the previous HF work. To be safe, we cleaned the inside of the hood with acid eater again and all the HF equipment were taken away from the chemlab.

No other issues to report.

Gas Lines/manifold

No issues to report.

GC3/NGA1

Both GCs were calibrated. NGA1 was not used. All headspace samples were analyzed on the GC3. One Vac sample was taken and run on the GC3. There were no issues with either unit.    

Hydrogen generators

No issues with the hydrogen generators. Started refit of generator 2 using one of the 24 month maintenance kits. Initially turned on to see if issue that was encountered on 368T would happen. It didn’t; the generator worked fine. Still opened up and used one of the 24 month maintenance kits. Those kits come with replacement pumps and floats but there was no instruction on replacing those, and water was still in those parts after draining the system. I saw how to get to those parts but held off on replacing them at the moment. Otherwise, generator 2 is working with no issues.

IC

The IC was used to measure cations and anions on the IW samples. Had some problems with bad calibations and reproducibility at one point. Was especially bad for cations. Changed guard column and in line filters. Performed cleaning procedures for suppressor, columns and sample lines. Eventually found that the sample tubing from the ultrafiltration membrane filter to the IC was contaminated and dirty; it was replaced. I hadn’t done a close look at the sample tubing initially, as it wasn’t a flow or pressure problem that would lead me to check the tubing. Other than that, no issues to report.

ICP

The ICP was used to measure IW samples and sediment samples. The first time using the ICP this expedition we weren’t getting argon flow to the ICP. It was discovered that the wall mounted regulator was blocked or stuck. It was replaced with a spare regulator.

In response to the 382 tech report; we used method with reduced number of lines. Copied from the lines we reduced to on 379. Still need to clean up the method as the only change done was to hide all unused lines. The lines could still be reduced more or selected differently.

Scientists selected the NOD-A1 standard for use in calibration. Could never get it to fully dissolve though. Some elements, it fit in with calibration lines, but for other it was obviously off. Not trusting it, it was usually turned off to leave out of the calibration.

Installed spreadsheet uploader on the ICP pc so the data can be uploaded from that pc instead of always copying to another pc to upload.

salinity

The optical refractometer was used, with no issues to report.

SRA

The SRA was not used. 

Pipettors

One of the purple 500-5000 pipettes had become very sticky after some substance had made its way into the pipette. Disassembled the pipettor to clean it and performed a calibration check. The procedure for disassembly and calibration is in the Eppendorf SOP for pipettes. The pipette was within error limits given by the Eppendorf SOP manual.

titrations

alkalinity

Had a few error windows pop up. The last one was a buffer error on the titrator. Turning the titrator unit off and on again fixed it. Didn’t have any more error windows after that.

Every error window seems to always recommend contacting the developers, but for many of the errors they don’t know what it is or how to fix. In the case of the buffer error it was a problem with the titrator instrument, but an error window that tells you to contact developers would make someone think it’s a software problem. Could make for a small project to do some time, to update the error codes with better recommendations that can fix the error rather than only saying to contact the developers.

Chloride

The chloride titrator was used. Scientist didn’t like how sticky the bottle top dispenser could be, so it was replaced with a different dispenser. The sticky dispenser was cleaned and is not as sticky anymore; was used for nitric acid dispensing for dissolving beads.

Water system

Changed the filter in the prefilter trap under the counter.

TOC

The TOC Analyzer was not used. 

PFT GC

The PFT GC was not used. 

Misc

The new light was installed above the SRA.

Geochemists

Chandranath Basak
Inorganic Geochemist
Department of Geological Sciences
California State University Bakersfield
USA

Lisa C. Herbert
Inorganic Geochemist
School of Marine and Atmospheric Sciences
Stony Brook University
USA

Simone Moretti
Organic Geochemist
Germany

Rebecca A. Smith
Organic Geochemist
Geosciences
University of Massachusetts-Amherst
USA