378S Transit to Panama Chem Tech Report

Aaron Mechler & Chang Liu

Ampulator

The Adelphi ampoule sealer was not used.

Balances

No issues to report for the Cahn & Mettler balances.

Carver Presses/Squeezers

No issues to report.

Cary Spectrophotometer

The Cary was used to analyze ammonium and phosphate. Phosphate values were very low and it was found that the repeatability at values less than about 10uM was not very good. Detection limit may be up to 3-5uM. Most values measured this expedition were in the range.

CHNS

CHNS analyzer was used to measure Carbon, Nitrogen and Sulfur. No issues to report. CNS soil and BBOT were used as standards.

Coulometer

The lamp in the Coulometer was changed. The cell set up screen always shows 4095 and never changes. Something is not right with that; it should at the very least see some minor variations of a point or two. At the moment it seems like it doesn’t actually work and could use some investigation.

Freeze-drier

No issues to report.

Fume hoods

No issues to report.

Gas Lines/manifold

Not a fan of the gas monitoring software in the chem lab being a slave to the program in the LO office. Makes it difficult to know if something is wrong with the program. Had a few days were the values were frozen before it was noticed that something was wrong. Problem was due to the master in LO office having an error.

GC3/NGA1

Both GCs were calibrated. The new NGA2 was used for HS.

Hydrogen generators

Hydrogen generator used for SRA was detected with a problem of a decreasing pressure from 70 psi to 0 psi during the transit. Hydrogen generator was restarted and the beeping stopped, along with pressure coming back to the setting value.

IC

The IC was used to measure cations and anions on the IW samples. One of the peristaltic pump tubes for delivering sample needed to be replaced at the beginning. Thinking that it may be a good idea to always run multiple water flushes through the system before long breaks.

ICP

The ICP was used to measure IW samples and sediment samples. A third set of standards was used for IW samples. It was an alternate of the in house standards using IAPSO instead of the acidified synthetic seawater. The calibrations matched very well between the two except for Si and Ba. Si likely due to IAPSO being stored in glass; Ba is still a mystery as the signal was near zero despite Ba having been added. Noticed that the 100% IAPSO standard was slightly off. Thinking it’s due to lack of acidification. Thinking about trying to spike standards with HNO3 the same as samples.

The standards used for sediment ICP were BCR-2, BIR-1, BHVO-2, DNC-1, NBS-1c, PACS-3, W-2, SCo-1, AGV-1.

Salinity

No issues to report.

SRA

The SRA was used. I found the source of one of the problems from 385. A missing o-ring that wasn’t replaced on the pedestal when trying to diagnose the initial fid problem. While results afterwards were improved, they were still not as good as the were at the beginning of 385.

The FID lighting problem continues. It appears to be an issue with some valves in the gas flow that are being shut off. Not sure why it’s happening but it may be worth trying to replace them at some point. 

Pipettors

No issues to report. Pipettors were collected and inventoried to be sent home for calibration.

Titrations

Alkalinity

The alkalinity titrator was used. No issues to report.

Chloride

The chloride titrator was not used.

Water system

Change the prefilter and carbon filter in the RO unit.

TOC

The TOC Analyzer was not used. 

PFT GC

The GC2 was not used.

Microbiology

MBIO samples were taken from Hole A and no issues to report.

Geochemists

Eleni Anagnostou
Inorganic Geochemist
Research Unit: Paleo-Oceanography
Research Division 1: Ocean Circulation and Climate Dynamics
Germany

Ann G. Dunlea
Inorganic Geochemist
Department of Geology and Geophysics
Woods Hole Oceanographic Institution
USA

Blanca Ausín
Organic Geochemist
Department of Geology
University of Salamanca
Spain

Open