Environmental chemistry

This sub-group also extensively utilises its ISO17025 accredited analytical chemistry facilities, both as a service to commercial clients through our external consultancy organisation (James Hutton Limited) and as an integral research tool across the Environmental and Biochemical Sciences Group and other groups within The James Hutton Institute.

Chemical transport processes

Our work encompasses analytical measurements of carbon, nutrients, organic and inorganic contaminants as part of developing knowledge on their interactions, transport and fate from soil to ground/surface waters and along the riverine continuum under different land use and management systems. Much of our work on contaminants within agriculture and urban water environments incorporates specialised analytical techniques for detection of inorganic trace metals/metalloids and organic compounds, such as pesticides, steroid oestrogens and pharmaceutical and personal care products.

Inorganic analysis:

Elemental analysis is carried out using a combination of Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma – Mass Spectroscopy (ICP-MS) for samples with element concentrations ranging from percentages to ppb. Ultra low level analysis for elements Hg, As and Se can be carried out to ppt levels on specialist cold vapour and hydride analysis equipment. With a variety of specialist sample preparation techniques, elemental analysis can be carried out on a variety of sample types from clean waters to brine samples and from soil samples to sediments. Other instruments include Ion Chromatography for anion analysis and discrete colourimetric techniques for ammonium and phosphate on water samples, and dedicated analysers for TOC and TN on both soil and water samples.

Organic analysis:

Organic analysis methodologies involves sample preparation, extraction and analyses of organic compounds found in different environmental matrices including plants, soils, sediments, water and sewage. We have the capacity to determine biologically derived organics (e.g. PLFA, organic acids, pigments, alkanes and amino acids) and organic contaminants, such as PAHs, PCBs, PBDEs, POPs and EDCs. Furthermore, we are continually developing detection methods for emerging/new organic compounds particularly in complex environmental matrices. Instrumental to this work are analytical techniques such as Gas Chromatography (GC-MS; GC-ECD/FID) and High Performance Liquid Chromatography (HPLC).

Organic matter characterisation:

Forming part of the National Waters Inventory for Scotland, spectroscopic analysis (UV-Visible absorbance and fluorescence spectroscopy) allows for rapid characterisation and fingerprinting of dissolved organic matter that influences biological and physico-chemical processesing natural aquatic environments as well as influences on the potential efficiency of water treatments, i.e. production of disinfection by-products, such as trihalomethane and quenching of UV light to pathogens.