Dataset: Hg Isotopes Particles
Deployment: KM1418

Mercury stable isotope values for marine particles

Principal Investigator:

Joel D. Blum (University of Michigan)

Co-Principal Investigator:

Claudia R. Benitez-Nelson (University of South Carolina)

Jeffrey C. Drazen (University of Hawaiʻi at Mānoa, SOEST)

Brian N. Popp (University of Hawaiʻi at Mānoa, SOEST)

Kanesa Seraphin (University of Hawai'i, UH)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Collaborative Research: Isotopic insights to mercury in marine food webs and how it varies with ocean biogeochemistry (Hg_Biogeochemistry)

Current State:

Final no updates expected

Data URL:

https://www.bco-dmo.org/dataset-deployment/788762/data

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Description

This dataset contains the mercury stable isotope ratios collected in marine particles during R/V Kilo Moana cruises around Station ALOHA. For more information about the ALOHA observatory see: http://aco-ssds.soest.hawaii.edu/. These data were published in Motta et al., (2019) with supporting information.

Methods & Sampling

Dataset acquisition description

Small (1-53 µm) and large (>53 µm) marine particles were sampled on all three cruises using in situ pumps (WTS-LV, standard, 8 L min⁻¹; McLane Research Laboratories, East Falmouth); water was passed sequentially through 53 μm pore-size nylon mesh and 1 μm pore-size quartz microfiber (QMA) filters with 142 mm diameter using a mini-MULVFS filter holder (Bishop et al., 2012). On the spring cruise, one pump was equipped with a pump head and motor with a maximum flow rate of 30 L min⁻¹, and high volume samples of particles >53 µm were collected. The large particles collected on the nylon mesh were sonicated and concentrated into a pre-combusted 47 mm QMA filter.

Marine particles were collected in two size fractions, small particles in combusted quartz filters (1-53 μm) and large particles in a nylon mesh (> 53 μm) using in situ McLane pumps during the three research cruises.

The marine particles were analyzed for total Hg concentrations by acid assisted microwave digestions and aliquots were analyzed by cold vapor atomic fluorescence spectrophotometry.

For THg isotope determination samples were combusted in a two-stage combustion furnace and Hg(0) g was trapped in a 1% KMnO4 solution. The 1% KMnO4 solution was analyzed for Hg stable isotope composition using a multiple collector inductively coupled plasma mass spectrometer.

All the methods are detailed in Motta et al., (2019).

Data Processing Description

Dataset Processing Description

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1433846	NSF Division of Ocean Sciences

Instruments

Cold Vapor Atomic Fluorescence Spectrophotometer

Supplied Name: cold vapor atomic fluorescence spectrophotometry

Supplied Description:

Instrument Type

Generic Name: Cold Vapor Atomic Fluorescence Spectrophotometer

Acronym: CVAFS

Generic Description:

A Cold Vapor Atomic Fluorescent Spectrophotometer (CVAFS) is an instrument used for quantitative determination of volatile heavy metals, such as mercury. CVAFS make use of the characteristic of mercury that allows vapor measurement at room temperature. Mercury atoms in an inert carrier gas are excited by a collimated UV light source at a particular wavelength. As the atoms return to their non-excited state they re-radiate their absorbed energy at the same wavelength. The fluorescence may be detected using a photomultiplier tube or UV photodiode.

Inductively Coupled Plasma Mass Spectrometer

Supplied Name: MC-ICP-MS

Supplied Description:

multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS; Nu instruments)

Instrument Type

Generic Name: Inductively Coupled Plasma Mass Spectrometer

Acronym: ICP Mass Spec

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB15/

Generic Description:

An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer.

McLane Large Volume Pumping System WTS-LV

Supplied Name: WTS-LV

Supplied Description:

in situ pumps (WTS-LV, standard, McLane Research Laboratories)

Instrument Type

Generic Name: McLane Large Volume Pumping System WTS-LV

Acronym: WTS-LV

Generic Description:

The WTS-LV is a Water Transfer System (WTS) Large Volume (LV) pumping instrument designed and manufactured by McLane Research Labs (Falmouth, MA, USA). It is a large-volume, single-event sampler that collects suspended and dissolved particulate samples in situ.

Ambient water is drawn through a modular filter holder onto a 142-millimeter (mm) membrane without passing through the pump. The standard two-tier filter holder provides prefiltering and size fractioning. Collection targets include chlorophyll maximum, particulate trace metals, and phytoplankton. It features different flow rates and filter porosity to support a range of specimen collection. Sampling can be programmed to start at a scheduled time or begin with a countdown delay. It also features a dynamic pump speed algorithm that adjusts flow to protect the sample as material accumulates on the filter. Several pump options range from 0.5 to 30 liters per minute, with a max volume of 2,500 to 36,000 liters depending on the pump and battery pack used. The standard model is depth rated to 5,500 meters, with a deeper 7,000-meter option available. The operating temperature is -4 to 35 degrees Celsius.

The WTS-LV is available in four different configurations: Standard, Upright, Bore Hole, and Dual Filter Sampler. The high-capacity upright WTS-LV model provides three times the battery life of the standard model. The Bore-Hole WTS-LV is designed to fit through a narrow opening such as a 30-centimeter borehole. The dual filter WTS-LV features two vertical intake 142 mm filter holders to allow simultaneous filtering using two different porosities.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Cruise_Number	Cruise ID number	unitless	cruise_id
Date	Sampling date (UTC); format: yyyymmdd	unitless	date
Mean_Depth	Mean depth of sample	meters (m)	depth
Size_fraction	Size fraction	micrometers (um)	samp_fraction
d202Hg	Stable isotope ratio; δ202Hg	per mil (‰)	no_bcodmo_term
D199Hg	Stable isotope ratio; Δ199Hg	per mil (‰)	no_bcodmo_term
D201Hg	Stable isotope ratio; Δ201Hg	per mil (‰)	no_bcodmo_term
D200Hg	Stable isotope ratio; Δ200Hg	per mil (‰)	no_bcodmo_term
D204Hg	Stable isotope ratio; D204Hg	per mil (‰)	no_bcodmo_term

Database

Contribute Data

Dataset: Hg Isotopes Particles
Deployment: KM1418

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Hg Isotopes ParticlesDeployment: KM1418

Dataset acquisition description

Dataset Processing Description

Dataset: Hg Isotopes Particles
Deployment: KM1418