Nutrients: 
Oxygen determination according to Winkler-Carpenter by means of a SIS Dissolved 
Oxygen Analyser (DOA) with photometric end point determination at selected depths. 
Determination of the pH value (CTD samples and continuously via the sea water pipe). 
Determination of depth of visibility by means of a Secchi disk at daylight stations. 
Filtration of surface water samples and freezing of the glass fiber filters for the 
determination of chlorophyll according to Jeffrey and Humphrey after the cruise. 
Determination of sea water alkalinity. 
Radiochemistry: 
2 x 35 I surface water for the extraction of strontium-90 after the cruise. 
One liter surface samples for the analysis of tritium after the cruise. 
150 I surface water samples for the on-board analysis of cesium-137 by means of an ion 
axchanger (KNIFC-PAN). 
100 | surface water samples for the on-board analysis of transuranic elements. 
Organic Pollutants 
Determination of polar and non-polar organic pollutants as, e.g. pesticides, chlorinated 
aydrocarbons (CHC), polycyclic aromatic hydrocarbons (PAH). 
Celtic Explorer at sea. Painting by Rosa Velten according to a photo of Declan Horan