Dataset: SOTS Si profile
Deployment: IN2023_V04

Programmable Flow Injection (pFI) silicate vertical profile data

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/931849

Principal Investigator:

Maxime Grand (Moss Landing Marine Laboratories, MLML)

Contact:

Maxime Grand (Moss Landing Marine Laboratories, MLML)

BCO-DMO Data Manager:

Sawyer Newman (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Collaborative Research: Developing Automated Nutrient and Trace Metal Methodology using Programmable Flow Injection (pFI-SI-LOV)

Version:

Deployment Synonyms:

INIV

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Description

Methods & Sampling

Dataset acquisition description

Unfiltered seawater samples were collected from the Niskin bottles in acid-washed plastic tubes. The stored samples were immediately analyzed for silicate in triplicate using the pFI assay protocol outlined in Hatta et al. (2021). One key modification was adjusting the holding coils’ temperatures to 25ºC instead of the originally specified 50ºC. In tandem with this temperature change, the stop flow time in the flow cell was extended to 60 seconds to ensure the absorbance of the silicomolybdenum blue at 810 and 660 nm product reached a steady state.

We used a miniSIA-2 instrument (miniSIA2, GlobalFIA, Fox Island, USA) equipped with a 8-port LOV unit and a 20 cm flow cell furnished with a Tungsten Halogen light source and UV-VIS spectrophotometer (Ocean Insight, USA) and a 14 position auto sampler (GlobalFIA, USA). The entire system was controlled with FloZF software (v 5.2, GlobalFIA). The system was calibrated using silicate working standards prepared in low nutrient seawater (LNSW, (0-119 µmol L-1 Si)).

Data Processing Description

Dataset Processing Description

To accommodate the analysis of Si samples from full depth ocean profiles within the constraints of a 20 cm flow cell, a dual measurement wavelength approach was adopted. For low Si samples (< 40 µmol L-1), the difference between the baseline corrected absorbances at 810 nm and the 1050 nm reference was used. For high Si samples (> 40 µmol L-1), a singular, baseline corrected measurement wavelength at 660 nm was employed. Silicate concentrations were calculated using the mean absorbances (660 nm for Si > 40 µmol L-1 and 810-1050 nm for Si < 40 µmol L-1) and the intercept and slope of the corresponding calibrations curves (660 nm calibration curve for Si > 40 µmol L-1 and 810-1050 nm calibration curve for Si < 40 µmol L-1 ).

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1924539	NSF Division of Ocean Sciences

Instruments

Flow Injection Analyzer

Supplied Name: miniSIA-2 (GlobalFIA, Fox Island, USA)

Supplied Description:

Instrument Type

Generic Name: Flow Injection Analyzer

Acronym: FIA

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB36/

Generic Description:

An instrument that performs flow injection analysis. Flow injection analysis (FIA) is an approach to chemical analysis that is accomplished by injecting a plug of sample into a flowing carrier stream. FIA is an automated method in which a sample is injected into a continuous flow of a carrier solution that mixes with other continuously flowing solutions before reaching a detector. Precision is dramatically increased when FIA is used instead of manual injections and as a result very specific FIA systems have been developed for a wide array of analytical techniques.

Spectrophotometer

Supplied Name: UV-VIS spectrophotometer (Ocean Insight, USA)

Supplied Description:

Instrument Type

Generic Name: Spectrophotometer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB20/

Generic Description:

An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples.

Parameters

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Database

Contribute Data

Dataset: SOTS Si profile
Deployment: IN2023_V04

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: SOTS Si profileDeployment: IN2023_V04

Dataset acquisition description

Dataset Processing Description

Dataset: SOTS Si profile
Deployment: IN2023_V04