Analytical chemistry unit - Facilities

Extraction and digestion

Extraction and digestion.

Our Extraction and Digestion preparation labs are strictly controlled to eliminate contamination issues and quality is monitored using certified and in-house standard materials.
The Digestion Laboratory uses automated heating blocks for aqua regia and nitric/perchloric digestion for the determination of major and trace elements in both soil and plant material and microwave digestion is used for closed tube procedures.

The Extraction Laboratory processes a number of standard procedures including; pH, exchangeable cation determination and sodium bicarbonate extraction of soil for the determination of available phosphate (Olsen).

Major and trace element analysis

Major and trace element analysis.

Major and trace element analysis of soil, plant material and waters is carried out using Inductively Coupled Plasma Spectrometry. Optical Emission Spectrometry (ICP-OES) is used for samples with element concentrations ranging from percentages to ppb and Mass Spectrometry (ICP-MS) when ultra-low level analysis is required (ppb - ppt).

  • Perkin Elmer Optima 7300 DV ICP-OES
  • Perkin Elmer NexION 300X ICP-MS
Anion (colourimetric) analysis

Anion (colourimetric) analysis.

Two instruments for colourimetric analysis; a segmented flow analyser and a discrete analyser, offer the versatility to be able to analyse aqueous samples and complex matrices from % to ppb concentrations. Determinations include: NO3-N, NO2-N, NH3-N, Cl, Molybdate reactive P, SO4-S, Br, total soluble nitrogen (TSN) using UV digestion, total P and CaCO3 (alkalinity).

  • Skalar SanPlus Segmented Flow Analyser
  • Thermo Scientific Aquakem 250 discrete photometric analyser
Stable isotope analysis

Stable isotope analysis.

Total C and N, 13C and 15N in soil, plant and biological materials are measured using an elemental analyser linked to an Isotope Ratio Mass Spectrometer (IRMS). The 13C content of organic compounds (compound specific) is determined using gas chromatography-combustion-stable isotope mass spectrometry (GC-C-IRMS). 15N in N2O and N2 and 13C content CO2 are also determined by IRMS.

  • Isoprime100 coupled with an Elementar VarioMICRO Cube introduction
  • Sercon 20-22 coupled with a Carlo Erba NA2000 elemental analyser
  • Finnigan Mat Delta Plus GC-C-IRMS
  • Sercon 20-22 with GC combustion/pyrolysis module
  • Europa Scientific Trace Gas Analyser linked to Sercon 20-22.
Combustion analysis - total nitrogen and carbon

Combustion analysis - total nitrogen and carbon.

Total nitrogen and total carbon in soil and plant material is determined using one of two combustion analysers based on a modified version of the Dumas method, with carbon detection by Non Dispersive Infrared (NDIR) and nitrogen using a Thermal Conductivity (TC) cell. The two instruments have the capability of processing several thousand samples each year and cover a variety of sample weights using ceramic boats for larger samples and foil cups for samples where weight is limited.

  • Leco TruMac Total N and C Combustion Analyser
Carbon analysis

Carbon analysis.

Total organic carbon in solution, measured as Non Purgeable Organic Carbon (NPOC) is determined by UV persulphate oxidation or high temperature TOC analysis. Samples include: high salt extracts of soil (K2SO4), rain, drainage water and soil solutions. A Primacs AIC Analyser is used for the direct measurement of inorganic carbon in soils, by treating with phosphoric acid and heating in a closed system.

  • Shimadzu TOC / TN (high temperature) analyser
  • Shimadzu TOC-V (UV oxidation) TOC Analyser
  • Skalar Primacs AIC Analyser
Greenhouse gas analysis

Greenhouse gas analysis.

The following instrumentation is used for the determination of N2O, CH4 and CO2 in gas samples.

  • Perkin Elmer Clarus 500 GC with turbomatrix headspace auto-sampler
  • Perkin Elmer Clarus 580 GC with turbomatrix headspace auto-sampler

The DENIS system is an automated incubation system to measure emissions and study transformations of nutrients in soil. The system allows incubation of intact or repacked soil cores and measurement of gaseous emissions of NO, N2O, N2, CO2 and CH4 are carried out after the application of fertiliser. Labelled fertiliser can be applied and resulting 15N2O and 13C can be measured by means of an IRMS.

  • Denitrification incubation system (DENIS).
Biogeochemistry

Biogeochemistry.

The analysis of Lipids, lignin, carbohydrates and amino compounds are carried out using gas chromatography, gas chromatography-mass spectrometry (GC-MS) and GC-MS with on-line pyrolysis

  • Agilent Technologies GC-MS
  • Agilent Technologies 7890 GC
Ruminant nutrition analysis

Ruminant nutrition analysis.

Ruminant nutrition analysis includes; the analysis of selenium in soil and biological compounds, protein in forages; grass and forage samples for modified detergent fibre (MADF), acid detergent fibre (ADF), acid detergent lignin (ADL), neutral detergent fibre (NDF); and the analysis of water soluble carbohydrates and volatile fatty acids by HPLC Analysis.

  • PS Analytical LC hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS)
  • Fibertec 8000 (Foss)
  • Agilent Technologies 1260 HPLC with ELSD, diode array and fluorescence detectors
  • Isotope ratio mass spectrometer (IRMS)