Dataset: H2S from microsensor profiles of ex situ sediment cores collected in the Chesapeake Bay and measured during 2017-2018

Methodology:
High-resolution microsensor profiling of O₂, pH, and H₂S was performed on replicate sediment cores retrieved from the sampling sites, with 1 or 2 replicate profiles made per sediment core per analyte, using commercial microsensors operated with a motorized micromanipulator (Unisense A.S., Denmark). Sulfide (SumH2S) was calibrated with 5-point calibration using NaS2 (0-300 micromolar), and corrected with pH at the corresponding depth. Detailed methodology is given in Malkin et al., 2014.

Sampling and Analytical Procedures:
Replicate sediment cores were collected using a gravity corer (Uwitec; clear PVC liners, Ø = 8.6 cm), capped, kept in the dark at bottom water temperature in a water bath, and transported back to the laboratory, where they were held in a climate-controlled room. Microsensor profiling was conducted within 1 day of core retrieval.

Instruments:
Unisense A.S. microsensors (Denmark) and motorized micromanipulator system were used for data collection. The 4 channel microsensor multimeter was used, with the following microsensors: Ox-50, pH-200, and H2S-100. Each sensor was used consecutively and so resultant data is provided separately as individual datasets. SensorTrace Suite software was used for data collection.