Dataset: Total dissolved sulfide (TDS) and carbonyl sulfide (OCS) from surface fish and CTD rosette samples collected on the US GEOTRACES GP17-OCE cruise on R/V Roger Revelle (RR2214) in the South Pacific and Southern Oceans from December 2022 to January 2023

Total dissolved sulfide (TDS) and carbonyl sulfide (OCS) were collected from the Oceanographic Data Facility (ODF) Niskin bottles and the GeoFish and stored in 4 liter (L) polyethylene cubitainers. The cubitainers were rinsed 3 times with the sample before filling hermetically with approximately 1.5 L of seawater sample and stored in a refrigerator until analyzed at sea, within 8 hours of collection using the Radford-Knoery and Cutter (1993) method.

Roughly 100 milliliters (mL) of the seawater sample was used to rinse the gas stripping vessel, and then filled with 300 mL of seawater sample and purged with helium (120 mL/minute) for 2 minutes. After 2 minutes, the cryogenic trap was immersed in liquid nitrogen followed by injecting 1.5 M phosphoric acid and stripped/trapped the gases for 20 minutes before quantifying TDS and OCS using a gas chromatograph coupled with a flame photometric detector.

This method quantifies TDS as free ions and metal-sulfide complexes with detection limits of 0.2 picomoles per liter (pmol/L) for TDS and 1.3 pmol/L for OCS for 300 mL samples (Radford-Knoery and Cutter, 1993). Dissolved sulfide water samples were analyzed primarily in duplicate, occasionally triplicate when time permitted. To ensure accuracy, the H₂S and OCS gases were calibrated using permeation tubes whose permeation rates have been gravimetrically measured for 2 to 4 years. By trapping and measuring known amounts of permeated H₂S and OCS over a range of times, linear calibration curves for each gas were assembled daily and applied to unknown samples.