Dissolved micro-molar nutrient data from CTD cast bottle samples for AMT 11 cruise
Originator's Protocol for Data Acquisition and Analysis
The samples were collected from 9 - 10 bottles on 46 CTD casts during the cruise. They were sub-sampled into acid-clean 60 ml HDPE (nalgene) sample bottles. Analysis for nutrients was completed within 3 hours of sampling in most cases. Clean handling techniques were employed to avoid contamination of the samples. No samples were stored.
Macro-nutrient analysis was carried out using air-segmented-flow, colorimetric techniques, with a Technicon Autoanalyser II. The analytical chemical methodologies used were according to Brewer and Riley (1965) for nitrate, Grasshoff (1976) for nitrite, Kirkwood (1989) for phosphate and silicate, and Mantoura and Woodward (1983) for ammonium.
References Cited
Brewer P.G. and Riley J.P., 1965. The automatic determination of nitrate in seawater. Deep Sea Research, 12, 765-72.
Grasshoff K., 1976. Methods of seawater analysis. Verlag Chemie, Weinheim and New York, 317pp.
Kirkwood D., 1989. Simultaneous determination of selected nutrients in seawater. ICES CM 1989/C:29.
Mantoura R.F.C. and Woodward, E.M.S., 1983. Optimisation of indophenol blue method for the automated determination of ammonia in estuarine waters. Estuarine Coastal and Shelf Science, 17, 219-24.
Instrumentation Description
Not relevant to this data set.
BODC Data Processing Procedures
Data were submitted via email in an Excel spreadsheet archived under BODC's accession number PML030068. Data were submitted to BODC in Microsoft Excel spreadsheet format. Sample metadata (CTD cast and depth) were checked against information held in the database. There were no discrepancies.
The data were provided in micromoles per litre. These units were consistent with the BODC parameter code units and no conversions were necessary.
The data were reformatted and loaded in BODC's samples database under Oracle Relational Database Management System. Data were marked up with BODC parameter codes and loaded into the database. Individual samples were matched through rosette sampling bottle.
A parameter mapping table is provided below;
| Originator's Parameter | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| Nitrate+nitrite | µmol l -1 | Concentration of nitrate+nitrite {NO 3 +NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | NTRZAATX | µmol l -1 | n/a |
| Nitrite | µmol l -1 | Concentration of nitrite {NO 2 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | NTRIAATX | µmol l -1 | n/a |
| Phosphate | µmol l -1 | Concentration of phosphate {PO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | PHOSAATX | µmol l -1 | n/a |
| Silicate | µmol l -1 | Concentration of silicate {SiO 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | SLCAAATX | µmol l -1 | n/a |
| Ammonium | µmol l -1 | Concentration of ammonium {NH 4 } per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis | AMONAATX | µmol l -1 | n/a |
Data Quality Report
BODC were not advised of any data quality checks carried out by the data originator. There were no standout values noted during BODC processing.
Problem Report
Not relevant to this data set.
