Dataset: Hawaii Ocean Time Series Comparison
Deployment: KM2210

Phosphate profile data comparison between programmable Flow Injection (PFI) and AA3 Autoanalyzer methods

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/931765

Principal Investigator:

Maxime Grand (Moss Landing Marine Laboratories, MLML)

Student:

Marine Lebrec (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:

Coordinated Deployments:

HOT_cruises

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Description

Methods & Sampling

Dataset acquisition description

We collected unfiltered seawater samples directly from the Niskin bottles. One set was analyzed in triplicate for phosphate using the pFI analyzer calibrated with MQ standards (0-3 µmol L-1). The duplicate samples were frozen, shipped to Scripps Institution of Oceanography (SIO) Ocean Data Facility chemistry laboratory on dry ice and analyzed at SIO’s lab using an AA3 autoanalyzer.

The pFI analyzer was calibrated with working phosphate standards prepared in MQ water (0-3 µmol L-1). To calculate phosphate concentrations at each depth, we took the mean of the baseline corrected absorbance at 880 nm minus the reference absorbance at 1050 nm. Phosphate concentrations were then calculated using the slope and intercept of the MQ calibration curve.

pFI LOD: 0.06 umol/L

pFI precision: 4.1%

Data Processing Description

Dataset Processing Description

Quality flags represented in the primary data file

1 = good
2 = bad*
3 = below detection limit

Data were flagged when the data were inconsistent with adjacent depths and visual observation of the absorbance spectra confirmed an issue during the analysis.

More information about this dataset deployment

Funding

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

Instruments

Flow Injection Analyzer

Supplied Name: pFI analyzer (miniSIA2, GlobalFIA, USA)

Supplied Description:

One set of samples was analyzed using a pFI analyzer (miniSIA2, GlobalFIA, USA). This instrument was furnished with two High Flow milliGAT pumps with stainless steel heads, a plexiglass 8-port Lab-On-Valve, a 20 cm Long Path Linear Flow cell equipped with a Tungsten-Halogen lamp and a VIS-NIR Flame spectrophotometer (Ocean Insight, USA).

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.

Flow Injection Analyzer

Supplied Name: SIO's AA3 analyzer (Seal Analytical, USA)

Supplied Description:

Samples not analyzed with the mini SIA2 pFI analyzer were analyzed using a SIO's AA3 analyzer (Seal Analytical, USA) following the vendor's established GO-SHIP protocols.

Instrument Type

Generic Name: Flow Injection Analyzer

Acronym: FIA

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

Generic Description:

Spectrometer

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

Supplied Description:

Instrument Type

Generic Name: Spectrometer

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0460/

Generic Description:

A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Latitude	Water sample latitude in decimal degrees; a positive value indicates a Northern coordinate.	decimal degrees	lat
Longitude	Water sample longitude in decimal degrees; a negative value indicates a Western coordinate.	decimal degrees	lon
ISO_DateTime_UTC	Water sample date time in UTC.	unitless	DateTime
Date_UTC	Water sample date in UTC.	unitless	date
Time_UTC	Water sample time in UTC.	unitless	time
Depth	Water sample depth in the water column in meters.	meters (m)	depth
pFI_PO4	Phosphate concentration from pFI analyzer.	umol/L	PO43-
pFI_flag	pFI flag. 1 = good, 2 = bad, 3 = below detection limit.	unitless	q_flag
SIO_PO4	Phosphate concentration from AA3 analyzer (SIO).	umol/L	PO43-
SIO_flag	SIO flag. 1 = good, 2 = bad, 3 = below detection limit.	unitless	q_flag

Database

Contribute Data

Dataset: Hawaii Ocean Time Series Comparison
Deployment: KM2210

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Hawaii Ocean Time Series ComparisonDeployment: KM2210

Dataset acquisition description

Dataset Processing Description

Dataset: Hawaii Ocean Time Series Comparison
Deployment: KM2210