Metadata Report for BODC Series Reference Number 1978867

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Open Data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

Flow Injection Chemiluminescence System

The Flow Injection Chemiluminescence (FI-CL) technique is based on a flow injection method coupled with chemiluminescence detection. A FI-CL system is composed of individual components that are typically uniquely assembled for each analysis. The model and manufacturer of each component can vary.

A typical FI-CL system consists of peristaltic pumps, multiway valves, a flow injection valve, a preconcentration column and chemiluminscence detector, such as a photon-counting head. Peristaltic pumps are used to deliver the reagent, sample, buffer and wash solutions to the system's components, and multi way valves enable the sample and wash solutions to pass sequentially through the preconcentration column. The injection valve is used to transport the sample to the detector. Cycles of loading, washing and injection may be computer controlled.

Shimadzu RF-20 A fluorescence detector

A high-sensitivity fluorescence spectrometer used to identify and quantify trace-level components of liquid samples, for applications such as food, pharmaceutical and environmental analyses. The fluorescence detector uses the principle of Raman spectroscopy to excite the liquid sample with excitation light from a Xenon lamp, and breaks up the emitted fluorescence light with a fluorescence monochromator. It extracts the required fluorescence wavelengths and measures the intensity with a photomultiplier. The RF-20A is capable of ultra fast, high-sensitivity multi-component analysis using a wavelength switching by time program, and utilises a four-wavelength measurement function that detects each component at its optical wavelength. Optional additions include an Amino Acid Analysis System, a Reducing Sugar Analysis System, a Carbamate Pesticide Analysis System and a Synthetic Antibacterial Agent/Mycotoxin Screening System. The RF-20A achieves a water Raman S/N ratio of 1200, and the Xenon lamp lasts approximately 2000 hours. It also has a 10 ms response time, and a wavelength range of 0, 200 nm to 650 nm.

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/shimadzu_RF-20A_brochure.pdf

Clean pumped sea water supply

The system comprises a precision echosounder (PES) fish attached to a clean, reinforced tube (typically composed of braided polyvinyl chloride (PVC)). The fish is designed to be towed alongside a moving ship at a depth of one to three metres and water is drawn through the system by a clean pump. The tube usually leads to a clean laboratory on board the vessel, inside which samples are drawn for analysis. The system is typically used for continuous, underway, clean sampling (e.g., trace metal studies) of near surface waters.

Total dissolved trace metals from underway towed FISH samples for JC150

Acquisition description:

Sampling methodology

High-resolution underway surface samples were collected using a 'towfish' which was deployed off the starboard side of the ship. Surface seawater was pumped into the trace metal clean laboratory using a Teflon diaphragm pump (Almatec A-15) connected by acid-washed braided PVC tubing to a towed 'fish' positioned at approximately 2-3 m. Underway samples were collected every 2 hours along the transect between stations. Filtered samples for dissolved zinc and iron were collected through 0.8/0.2 µm polyethersulfone membrane filter capsule (Sartobran, Sartorius) into LDPE bottles and acidified, while the filtration step was omitted for the underway TDFe samples. No sFe samples were taken from the underway system. In all, 130 towed fish time point samples were taken along the transect.

Analytical methodology

Iron

All dFe and TDFe samples were analysed in triplicate using flow injection analysis with chemiluminescence detection (Birchill et al., 2017; Obata et al., 1993; 1997) inside a class 1000 clean air laboratory either on-board the R.R.S. James Cook or subsequently at the National Oceanography Centre Southampton, UK. Each sample was spiked one hour prior to analysis with 0.013 M ultrapure H₂O₂ (Sigma-Aldrich) in a ratio of 1 µl H₂O₂ per ml sample to ensure the complete oxidation of Fe(II) to Fe(III) (Lohan et al., 2006). Each sample was buffered in-line to pH 3.5-4.0 using 0.15 M ammonium acetate (Romil, SpA) before Fe(III) was selectively pre-concentrated onto the cation exchange resin Toyopearl-AF-Chelate 650 M (Tosohaas). Following the removal of the seawater matrix from the resin using a weak 0.013 M HCl (Romil, SpA) wash, the Fe was liberated from the resin using 0.24 M HCl (Romil, SpA) and entered the reaction stream. The eluent was mixed downstream with a 0.015 mM luminol solution containing 70 µl L-1 triethylenetetramine (both Sigma-Aldrich), buffered to pH 9.4-9.6 using 1 M ammonia solution (Romil, SpA) with the chemiluminescent reaction occurring following the addition of 0.4 M H₂O₂ (Rose & Waite, 2001). The light signal at a wavelength of 425 nm was detected by a photomultiplier tube and concentrations were quantified using standard additions to low Fe seawater. The limit of detection (3x the standard deviation of the lowest standard addition) was 0.03±0.02 nM (n = 59), whilst the precision of triplicate analysis was 2.78±2.02 % (n = 1764). The accuracy of the method was established by repeat quantification of dFe in the SAFe reference samples yielding values of 0.11±0.02 nM (n = 6) and 0.94±0.04 nM (n = 17) for SAFe S and SAFe D2 respectively, which are in close agreement with the reported consensus values (S = 0.095±0.008 nM; D2 = 0.96±0.02 nM).

Zinc

Following collection, all sub-samples were acidified (0.024 M HCl; Romil SpA) and then analysed onboard ship for DZn concentration using flow-injection analysis with fluorimetric detection, as first described by Nowicki et al. (1994). 20 mL of seawater was buffered in-line (pH 4.5) and then DZn pre-concentrated for 200 seconds onto a cation exchange resin (Toyopearl AF650 Chelate). The major seawater cations were rinsed from the resin with weak NH₄OAc before the DZn liberated from the resin with HCl and then mixed with p-tosyl-8-aminoquinoline (pTAQ, Sigma-Aldrich), which forms a stable fluorescent complex with Zn(II). The fluorescent reaction was measured by a Shimadzu RF-20A fluorimeter. Dissolved Zn was determined using two separate calibration curves, depending on ambient concentrations as Zn concentrations ranged from 30 pM to 4.5 nM at depth. Calibration standards were made using low Zn seawater collected from the towed 'fish'. Each sub-sample was run in triplicate with each complete analytical cycle taking 18 minutes. The analysis produced excellent analytical figures of merit with detection limits 10-30 pM and excellent agreement with SAFe and GEOTRACES reference samples.

Aluminium

All dAl samples were analysed in triplicate using flow injection analysis with fluroimetric detection (Resing & Measures, 1994; Brown & Bruland, 2008) inside a class 1000 clean air laboratory at the National Oceanography Centre Southampton, UK. Briefly, the sample was buffered in-line to pH 6 with 0.8 M ammonium acetate before being loaded onto a chelating iminodiacetic acid (Toyopearl AF-Chelate 650 M) preconcentration column. The column was rinsed using 0.01 M ammonium acetate to remove the seawater matrix cations before Al was eluted from the column with 0.1 M HCl (SpA, Romil). The HCl eluent entered the reaction stream where it mixed with a 4.8 mM lumogallion solution and 5% solution of Brij-35. The emission of the fluorescent complex was detected by a Shimadzu RF-10Axl fluorimeter with excitation and emission wavelengths set to 489 and 559 nm, respectively.

References Cited

Birchill, A. J., Milne, A., Woodward, E. M. S., Harris, C., Annett, A., Rusiecka, D., Achterberg E.P., Gledhill M., Ussher S.J., Worsfold P.J, Geibert W. and Lohan, M. C. (2017) Seasonal iron depletion in temperate shelf seas. Geophysical Research Letters, 44(17), 8987?8996. DOI: 10.1002/2017GL073881

Lohan M.C., Aguilar-Islas A.M., Bruland K.W. (2006) Direct determination of iron in acidified (pH 1.7) seawater samples by flow injection analysis with catalytic spectrophotometric detection: Application and intercomparison, Limnol. Oceanogr. Methods, 4, doi:10.4319/lom.2006.4.164

Nowicki J.L., Johnson K.S., Coale K., Elrod V.A., and Lieberman S.H. (1994) Determination of Zinc in Seawater Using Flow Injection Analysis with Fluorometric Detection. Analytical Chemistry 66. 2732-2738. 10.1021/ac00089a021.

Obata H.O., Karatani, H. and Nakayama E. (1993) Automated Determination of Iron in seawater by chelating resin concentration and chemiluminescence detection. Analytical Chemistry 65. 1524-1528. 10.1021/ac00059a007.

Rose A.L. and Waite T. (2002) Chemiluminescence of Luminol in the Presence of Iron(II) and Oxygen: Oxidation Mechanism and Implications for Its Analytical Use. Analytical chemistry. 73. 5909-20. 10.1021/ac015547q.

Obata H., Karatani, H., Matsui M. and Nakayama E. (1997) Fundamental studies for chemical speciation of iron in seawater with an improved analytical method. Marine Chemistry. 56. 97-106. 10.1016/S0304-4203(96)00082-5.

BODC Data Processing Procedures

Data received were loaded into the BODC database using established BODC data banking procedures. A parameter mapping table is provided below:

Project Information

Zinc, iron and phosphorous co-limitation in the Ocean: ZIPLOc

ZIPLOc is an 3 year project that aims to measure how zinc and phosphorous control biological activity in the North Atlantic subtropical gyre using novel measurement techniques. The observations made will be further explored using the latest modelling techniques over decadal timescales and in other basins.

The research aims to make an improvement in our overall understanding of how subtropical gyre ecosystems respond to ongoing climate change.

The project is led by the University of Liverpool, Earth, Ocean and Ecological Sciences and is a collaboration with the University of Southampton, School of Ocean and Earth Science. The project received funding from the Natural Environmental Research Council and runs between January 2017 and February 2020.

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle: