Search the data

Weekly samples of Dissolved Organic Carbon and Dissolved Organic Nitrogen at three shore-based sites around Christchurch Harbour, Dorset for the Macronutrients project

Originator's Protocol for Data Acquisition and Analysis

Dissolved organic carbon and dissolved organic nitrogen data from a weekly sampling programme at Knapp Mill on the Hampshire Avon, Throop on the Stour and Mudeford in Christchurch Harbour. The sampling period started on 25 ^th April 2013 and ended on 10 ^th April 2014 and forms part of the Christchurch Harbour Macronutrients Project.

Samples were collected using a bucket from the surface, immediately decanted into combusted glass bottles triple-rinsed with sample, and transported to lab in cool boxes. Samples were filtered through combusted GF/F filters on an acid-washed glass filter rig under minimal vacuum pressure. Triplicate samples of 20 mL each were poured into combusted glass vials, preserved with 60 mL 50 % (v/v) phosphoric acid, and sealed with acid washed teflon septa and cap. Samples were stored in refrigerator until analysis.

Instrumentation Description

Samples were analysed using high-temperature catalytic oxidation on a Shimadzu TOC-Vcph at the National Oceanography Centre, Southampton. The dissolved organic nitrogen concentration was determined from the total dissolved nitrogen concentration by subtracting the corresponding nitrate and nitrite concentrations

Some dissolved organic nitrogen data negative once nitrate and nitrite concentrations subtracted. These have been reported as 'below detection limit' and are a result of the very high inorganic nitrogen concentrations in the samples.

BODC Data Processing Procedures

Data received were loaded into the BODC database using established BODC data banking procedures.