IUPUI Biogeochemistry Lab
Facilities

The 1000 sq. foot trace element geochemistry laboratory is equipped with acid fume hoods, flow benches, balances, an enclosed instrument room, and computers.

A Leeman Labs P950 Inductively Coupled Plasma - Atomic Emission Spectrometer (ICP-AES), is used for all elemental analyses. The instrument is a fully operational, sequential ICP-AES with a shortwavelength detector and a CETAC Corp. AT5000 ultrasonic nebulizer, and an argon-purged optical path for high precision determinations, a 120 sample Autosampling package, an Eschelle grating. The instrument provides elemental determinations on the parts per billion level in a wide range of sample matrices, and its multi-element capability yields the potential of determining about 16 elements per minute on individual samples.

The newest addition to the biogeochemistry lab is the Leco Corp. AMA254 Advanced Mercury Analyzer.  The single purpose absorption spectrophotometer is designed for rapid, accurate, and simple determination of trace mercury in liquid and solid samples.  There is no pretreatment required, and the results are matrix independent.  The liquid/solid sample is introduced into the instrument and thermally treated during the analysis process.  The sample is initially dried prior to combustion in an oxygen atmosphere.  All the mercury vapor evolved during the combustion process is trapped quantitatively on the surface of a gold amalgamator.  The preconcentration of mercury is then evaporated and measured, with results in as little as five minutes. 

A UIC Coulometrics CM150 carbon analyzer, is also housed in the geochemistry lab and is used for carbon determinations. This coulometer automatically measures the absolute mass amount of carbon dioxide resulting from the combustion or acidification of a sample. Inorganic C is measured by acidification, and total C is measured directly by combustion. The furnace temperature can reach 1100 BAC, a level shown to be adequate for the complete combustion of organic matter. No user-calibration is required and linear detection is available from less than 1 mg to over 10,000 mg C, providing an excellent working range for a variety of sample compositions.

A Shimadzu UV-2401PC Spectrophotometer system is used primarily for phosphate and silicate determinations.  It features a single monochromator with a high-performance blazed holographic grating in the aberration corrected Czerny-Turner mounting, and a Sipper 160.  The wavelength range is from 190 nm to 900 nm, with a 0.1 nm resolution.  The photometric system uses a double-beam, direct ratio system with dynode feedback. The low stray light/wide dynamic range/small beam size combination makes this instrument well suited to handle a variety of practical situations.

A CEM Corp. MDS-2000 microwave digestion system can be used for digesting, dissolving, hydrolyzing, or drying a wide range of materials.  The primary usage in the IUPUI Biogeochemistry lab is performing total disgestions on samples to prepare them for ICP-AES analysis.