Jenna and Sina sat down and compiled a list describing each of the instruments here at The Evergreen State College….
Atomic Absorption Spectrometer (AA)
The AA is typically used for qualitative and quantitative elemental analysis. It is a technique where liquid samples are atomized via acetylene flame and the interaction of these atoms with specific wavelengths of light are measured via photomultiplier. Generally, one element can be analyzed at a time.
Analysis Range: ppm
Inductively Coupled Plasma – Mass Spectrometer (ICP-MS)
The ICP-MS is used for qualitative and quantitative multi-elemental analysis. In this technique, liquid samples are ionized via plasma torch. Ions are then separated based on their mass to charge ratio and detected via electron multiplier. Multiple elements can be analyzed at a time.
Analysis Range: ppb
Mercury Analyzer (not currently being taught – possible sample processing)
The mercury analyzer determines the concentration of mercury in liquid and solid samples. It uses thermal decomposition and chemical reduction to produce mercury gas which is detected by UV spectroscopy.
Analysis Range: 0.002-2000ng
Carbon, Hydrogen, Nitrogen Analyzer (not currently being taught – possible sample processing)
The CHN Analyzer uses thermal decomposition and chemical reduction to determine carbon, hydrogen, and nitrogen concentrations in solid samples.
Discrete Analyzer (not currently being taught – possible sample processing)
The discrete analyzer is a multi-chemistry instrument that can be used for quantitative and qualitative analysis. It can be used with liquid samples or liquid extracts of solid samples. Reagents need to be prepped in the lab and then are dispensed into wells by the user. The instrument mixes the reagents for each analysis, detects the signal, creates a calibration curve and displays the results. Common analyses include nitrate, nitrite, ammonia, phosphate, alkalinity
Ion Chromatograph (IC) (currently only testing for anions is available)
The IC is used primarily in water analysis to determine concentrations of common ions
such as chlorine, fluorine, nitrite, nitrate, phosphate and sulfate. It uses packed columns
to separate cations or anions in liquid samples which are detected with a conductivity
Analysis Range: low ppm to high ppb
Polarograph (not currently available)
The polargraph uses an electrode to generate a current from cations or anions in solution.
The unique patterns of these currents are compared to standard solutions. The polargraph
is used for quantification and qualification of common ions such as nitrite, nitrate,
phosphate, chlorine, and sulfate, functional groups in organic compounds, and metallic
ions in solution.
Analysis Range: low ppb
Fourier Transform Nuclear Magnetic Resonance Spectrometer (FTNMR)
The FTNMR is used to gather qualitative and quantitative information. A liquid sample,
containing organic molecules, is bombarded with RF radiation. It then picks up signals
given off by hydrogen atoms of a compound to determine unique hydrogen environments
present in an unknown molecule, and the number of hydrogen atoms in each unique
environment. Molecular structure may be deduced via FT-NMR.
Gas Chromatograph Mass Spectrometer (GCMS)
While normally used for qualitative purposes, the GCMS can also be used to gather
quantitative data. Liquid samples, with boiling points below 250ºC, are heated to reach a
gas state, which passes through a coated capillary column. The sample is separated into
distinct compounds based upon boiling temperature and attraction to the lining of the
column. After separation the compounds enter the mass detector where each compound
is fragmented. The compound fragmentation results in a set of unique patterns that can
be compared to a standard.
Analysis Range: ppb
Fourier Transform Infrared Spectrometer (FTIR)
The FTIR uses infrared radiation to determine compound constituents and functional groups within a molecule. Gas, liquid or solid samples are bombarded with infrared radiation. Each molecule or component of a molecule absorbs the infrared radiation at specific wavelengths. These absorption patterns are diagnostic for specific molecules or components. Generally, the FTIR is used to gather qualitative information.
The Automontage is a research grade dissecting/stereomicroscope that takes multiple images at different depths and montages images to create a final image with an improved depth of field.
Magnification: 5 – 115X
The Zeiss is a research grade compound microscope with better resolution which allows higher magnification over our standard compounds. It can be set up for bright field, dark field, phase contrast, and differential interference contrast microscopy.
Magnification: 63 – 2000X
The Confocal is a research grade inverted compound microscope set up for bright field, differential interference contrast, wide field flouorescence/epifluorescence, and confocal microscopy. You must have a driver’s license on the Zeiss before training on the Confocal.
Magnification: 40 – 1600X
Scanning Electron Microscope
The SEM uses an electron beam to generate an image of the surface of solid objects. This electron beam allows far greater magnification, resolution, and depth of field than general light-based microscopy.
Magnification: 8 – 300,000X