The Analytical Laboratory contains a wide range of instrumentation for research into marine biogeochemistry. The instruments are kept separate from the Analytical Laboratory Preparation Room where much of the wet chemistry and fume-cupboard acid and organic solvent work is carried out.

Nutrient chemistry (ammonia, phosphate, silicate and nitrate) in water and sediment samples can be analysed using two Lachat Auto-analysers. These instruments rely on flow injection analysis and spectrophotometric detection using classical wet chemistry techniques. In addition to these inorganic nutrients, dissolved organic nitrogen and phosphorus can also be analysed.

 A range of other ions involved in marine biogeochemical processes such as sulphate and sulphide are measured using the Dionex ICS-2000 ion chromatography instrument. Other recent work has included measurement of bromide ion tracers in bioturbation studies.

A range of photosynthetic pigments (chlorophyll a,b; carotinoids etc.) found in algae and photosynthetic bacteria can be measured using the High Performance Liquid Chromatography (HPLC) facilities which use single pump isocratic and dual pump gradient elutant methodologies. Detection is by fluorimetry and/or spectrophotometric techniques

Dissolved inorganic and organic carbon fractions in sea water samples are measured using our Shimadzu TOC-V instrument. Using flash combustion and catalysis, the sea water samples are oxidised and the liberated carbon dioxide is measured by infra-red spectroscopy. In addition, dissolved nitrogen is measured alongside the carbon using thermal conductivity.

Particulate carbon and nitrogen from sediment and water samples are measured using two elemental combustion instruments: the Costech EC and the PDZ Europa. The PDZ also allows the naturally occurring isotopic ratios of C¹²/C¹³ and N¹⁴/N¹⁵ to be measured.

The lipids gas chromatography (GC) facilities, incorporating GC mass spectrometry, are used for determining and identifying marine lipids in sediment, water and organism samples. These can be used to determine carbon sources in the marine environment and the feeding habits of selected organisms. In addition, the long carbon chain ketones known as alkenones are also analysed and are used to determine palaeo-sea temperatures in marine sediment cores.

Our biogas GC facilities are used to determine the concentrations of the Dimethyl Sulphide (DMS) suite of chemicals (DMSO, DMSP) in the marine environment. DMS is a product of algal and bacterial metabolism and when released from the sea surface into the atmosphere it acts as a cloud seed. In addition, bacterial production of methane (pelagic methanogenesis) is also measured using the Biogas GC facilities.

Marine sediment elemental concentrations of major metals (e.g. Fe, Al, Mg, K, Ca etc.) and minor metals (e.g. Mn, Cr, Ni, Cu, Zn etc.) are measured using the Perkin Elmer Induction Couple Plasma Optical Emission Spectrometer, ICPOES. This instrument can measure a wide range of metallic elemental concentrations from acid dissolved sediment samples and yields information alongside the trace elemental data obtained from the SAMS ICP Mass Spectrometer.

For more information, please contact the lab manager, Mr Tim Brand.