External Services

Our Thermo-Fisher Element 2 sector-field ICP-MS allows for precise and accurate measurements of most elements of the periodic table, in concentrations ranging from parts per trillion (ppt) to parts per million (ppm), with capability and detection limits varying per element (and generally best for metals and heavy atomic masses).

The Element 2 has a high mass resolution capability allowing for precise and accurate quantification of light mass elements typically prone to isobaric interferences. Samples are run against calibration standards of concentration ranges matching those of theFF samples. Blanks are also run in the same analytical session, for assessment of detection limits and laboratory and instrumental elemental backgrounds. Samples are run after addition of an internal standard, for more precise quantification.

For optimal results, it is preferred that samples be submitted in a weak nitric acid matrix (~1%). Users should consult with us before submitting samples, and inform us of the nature of their samples and the expected range of concentrations of their element(s) of interest. Improper sample preparation may result in a loss of data quality and extra sample preparation time in our laboratories, with extra associated charges.

We accept natural waters, aqueous solutions from experiments, digested inorganic or organic compounds, natural or man-made.

The ICP-MS above can be used in tandem with a Photon Machines Analyte G2 laser ablation system. The laser acts as a sampling device for the ICP-MS.

Elements can be quantified with concentrations in the order of sub-part per million to wt %, with capabilities that vary across the periodic table, as for stand-alone ICP-MS. Laser spot size can vary from 110 to 5 microns, with the largest spot sized preferred for best instrumental capability. Larger samples can also be rastered as surface scans with a wide beam, for optimal performance.

Samples are run against several calibration standards, and blank levels are subtracted to each analysis. Samples can be submitted as thin sections or 1-inch epoxy mounts. Custom sizes can be accepted after consulting with us, if they have a flat surface suitable for ablation and fit within our sample tray.

As for stand-alone ICP-MS, it is preferred that users know the matrix type of their samples and the expected concentration ranges of their element(s) of interest. Samples can consists of natural or synthetic minerals, glasses, metals, alloys, ceramics, bone and tooth tissues and fused powders.

Our Shimadzu XRF-1800 X-ray fluorescence spectrometer allows for quantitative or semi-quantitative analyses of major element compounds and some trace elements, in a variety of material types including powders, pressed powders, fused powders, films, and metal, glass or ceramics surfaces.

Sample sizes can vary from a few cm to a few mm in diameter. As with the LA-ICP-MS, results are the most robust for the largest sample sizes.

The XRF may be used in combination with the ICP-MS or LA-ICP-MS, upon user request, or at our discretion for materials of unknown composition. The XRF will only provide semi-quantitative results if no reference materials of matching compositions are available.

Our JEOL JSM-5610LV scanning electron microscope provides 50x to 50,000x secondary electron microscopy imaging of samples such as micro-fossils, microscopic minerals or dust, and elemental density information of polished surfaces by backscatter electron microscopy. Our SEM is also equipped with a Thermo Ultra Dry Energy Dispersive Spectroscopy (EDS) detector, allowing for semi-quantitative micro-analysis of major elements on polished surfaces.

We can accept epoxy mounts and petrographic thin sections.

The SEM can be used, upon user request, in tandem with the LA-ICP-MS for preliminary non-destructive EDS characterization of materials. The EDS detector also allows for elemental mapping of samples.

Our Siemens D-500 X-ray diffractometer (XRD) allows for semi-quantitative characterization of powdered crystalline minerals, natural or synthetic. As a non-destructive analytical technique, it allows for a sample analyzed by XRD to be analyzed further with other techniques available in the department.

LDIR (Laser Direct Infrared) Chemical Imaging System

Please contact Josh Schwartz at joshua.schwartz@niu.edu before sending samples

X-Ray Fluorescence (XRF)

There are three general types of measurement and analysis of samples. Accuracy of results and analysis time increase as you go down the list.

• Standardless: Uses XRF internal fundamental parameters to calculate the abundance of elements
• Standard reference: A standard with known values close in physical properties, and elemental composition and abundance to the unknown sample is measured and compared to quantify the unknown.
• Calibration curve: A series of standards that bracket the unknown sample is measured and compared to quantify the unknown.

Sample volume and preparation varies depending on your sample material and what you are measuring. If your sample requires preparation, we can advise on the method required or for an additional cost, we can perform the prep.

^[1]Academics that wish to be trained and run their own samples may be charged a reduced rate.

^[2]If using a reference material or calibration curve for these samples, some technician time will be involved to design, test and implement the appropriate procedure. The time needed to conduct that design, testing and implementation procedure will depend on your samples and elements of interest. Samples with more than 10 elements to be measured will be charged at different rates. Contact us with sample information for an estimate.

Scanning Electron Microscope (SEM) with Energy Dispersive Spectrometry (EDS)

SEM use is charged per the hour. The cost includes normal sample preparation, which is not part of the operation time. Academics and students that wish to be trained and run their own samples may be charged a reduced rate.

Isotope ratio mass spectrometry (IRMS) allows for measurements of the stable isotope ratios of light elements such as hydrogen, carbon, nitrogen, oxygen, sulfur, silicon at the natural abundance level in a broad range of samples.

Two Isotope Ratio Mass Spectrometers are used in the NIU Stable Isotope Laboratory (SIL), Thermo Fisher Scientific MAT 253 and Delta Plus Advantage. Samples can be analyzed directly in a dual inlet mode (e.g. CO₂, O₂, N₂ gas) or after conversion to these simple gases using various online techniques. Our laboratory is equipped with Elemental Analyzer (EA, Costech ECS 4010) that converts samples designated for carbon ¹³C/¹²C and nitrogen ¹⁵N/¹⁴N isotope analyzes to CO₂ and N₂ (Thermo-Finnigan DELTAplus Advantage). Samples frequently analyzed using EA include plant material, animal tissues, soil. In addition to the EA, a Gas Chromatograph (GC) is coupled to the same IRMS via a combustion interface (Thermo Fisher Scientific GC-C III), which allows us to analyze the stable carbon (¹³C/¹²C) or hydrogen (²H/¹H) isotopes of a single organic compound.

Gas Chromatograph is used for identification and quantitation of the semi-volatile compounds which are previously extracted from various environmental samples. A mixture of organic compounds in a liquid solvent is injected into an injector kept usually at a temperature between 200-300 °C. The sample instantly vaporizes and is carried in a stream of helium into a capillary column where it undergoes a separation based on the volatility and affinity of a specific compound to a stationary phase of the column. Separated compounds are transferred into an ion trap mass spectrometer, where they undergo the ionization and the detection.

Please contact Dr. Anna Buczynska at abuczynska@niu.edu before sending samples.

Cost per analysis: This pricing refers to "typical" samples. Prices listed are for "ready-to-run" samples. Please see the sample preparation section of each method for expectations. Extra fees may apply if other services are required. For commercial work, add appropriate sales tax. Please contact the lab for any questions or concerns.