Nutrients in water sampled during the PHYCOB cruise in the Southwestern Black Sea in 2021


Nitrite and nitrate as nitrogen (NO3+NO2), ammonium as nitrogen (NH4+), ortho-phosphate as phosphorus (o-PO4) and silica (SiO2) analyzes were measured by a QuAAtro39 Continuous Segmented Flow Analyzer consisting of an autosampler, a peristaltic pump, a chemistry manifold, a detector and data acquisition software. This protocol is in accordance with standard methods for the examination of water and wastewater. Dissolved oxygen (DO) was measured by using the Winkler method, in which a divalent manganese solution and strong alkali are added sequentially to the samples. Thus, dissolved oxygen rapidly oxidizes an equivalent amount of divalent manganese to basic hydroxides of higher valency states. With the presence of iodide ions in acidic conditions, the oxidized manganese reverts to its divalent state, and meanwhile, the iodine equivalent to the dissolved oxygen in the sample is released. This released iodine is titrated with a standardized thiosulfate solution and the dissolved oxygen value in the sample is calculated by potentiometric measurement using Metrohm 905 Titrando automatic titrator system. Dissolved oxygen samples are taken and analyzed in duplicate. The relative percent difference (RPD) of duplicates did not exceed 4.3% (Average is 0.62%). All results were also compared with the CTD dissolved oxygen data. pH measurements of sea waters were measured in lab by Mettler Toledo SevenMulti pH meter. The pH meter was calibrated every two days with the calibration standards at the values of 7.00 and 9.21. During the measurements, the pH values were recorded together with the current sample temperature values.

Data provider:Aslan Ertugrul

Related Identifier
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Metadata Access
Creator Aslan, Ertugrul; Krock, Bernd
Publisher PANGAEA
Publication Year 2024
Rights Data access is restricted (moratorium, sensitive data, license constraints)
OpenAccess false
Resource Type Dataset
Format text/tab-separated-values
Size 672 data points
Discipline Earth System Research
Spatial Coverage (28.125W, 42.233S, 31.048E, 44.582N)
Temporal Coverage Begin 2021-09-12T04:20:00Z
Temporal Coverage End 2021-09-17T10:00:00Z