Absorbance and fluorescence spectrometer

The Horiba Duetta can run both fluorescience and absorbance simulataneously in liquid and solid samples. We use it primarily to characterize organic matter in natural waters. We can generate EEMS (Excitation Emission Matrix) from 250 nm to 1100 nm with a Fluorescence Sensitivity Specification of 6,000:1 RMS for Water Raman. The Duetta can automatically correct for Primary and Secondary Inner Filter Effects (IFE).

Total organic carbon and total nitrogen analyzer

We use our new Elementar enviroTOC to primarily measure dissolved organic carbon (DOC) and total nitrogen (TN) in water samples. The instrument can also run dissolved inorganic carbon and total organic carbon (unfiltered samples).

Our enviroTOC is capable of measuring down to low ppb concentrations (with up to 1 mL injection volume) for both DOC and TN, and can measure both fresh and saline samples with relative ease. The autosampler can hold up to 60 samples and standards. 

Flow injection analyzer for nutrients

We have two FIA Lab FLEX systems installed, capable of measuring down to sub-ppb concentrations of soluble reactive phosphorus (SRP), nitrate, nitrite, ammonia and dissolved silica (silicic acid). We are able to run two of the above chemistries simultaneous on ~1 mL of sample in just a couple of minutes. Switchover of chemistries is quick and takes only a few minutes.

The FLEX systems have a choice of 10 cm or 5 cm flow cells for high sensitivity. The CETAC autosampler can hold up to 180 samples with 10 additional standards. Our FLEX systems have the added benefit of being equipped with spectrometers instead of photodiodes, meaning wavelength selection is done through the software. All wavelengths are recorded simultaneously for post-processing tasks.

We regularly run water samples and sediment leach solutions on our analyzer.

Direct Mercury Analyzer

The DMA-80 is used for analyzing sediment samples (on filters or just sediment) for total mercury (Hg), but can also be used for tissues and high level liquids. It’s a very simple instrument to operate and is often used by undergraduates in our lab. Samples are loaded into nickle or quartz boats and then placed into the autosample tray – no other sample prep is needed. The sample is thermally decomposed inside the instrument (at close to 1000 deg C), the mercury converted to elemental form, trapped on a gold amalgamator and measured on a Atomic Absorbsion Spectrometer. A measurement takes only ~6 minutes. 

Our DMA-80 is the tri-cell version, which means it can measure down to parts per trillion concentrations (<ng of mercury) in sediments and parts per billion in liquids (due to limited sample size).

Total Mercury Analyzer

While the DMA-80 is used for “high” level mercury samples, the Tekran 2600 is used for low to very low level mercury samples. The 2600 measures total mercury via cold vapor atomic fluorescence spectroscopy (CV-AFS) using EPA Method 1631. All of the mercury in a sample is digested to inorganic mercury using BrCl and reduced to elemental Hg by use of stannous chloride, followed by in vial sparging, trapping/pre-concentration, desorption, and analysis of Hg by CV-AFS. The detection limit of this instrument goes down to 0.02 ng/L, which is often necessary for natural waters.  Our Tekran 2600 is located in a Class 10,000 cleanroom and has a dedicated Class 100 flow hood for sample preparation.

Methyl-mercury Analyzer

The Tekran 2700 methylmercury analyzer runs EPA Method 1630 and variations of that method. The 2700 measures concentrations of inorganic mercury, methylmercury, and elemental mercury, separated in a built-in GC oven with capillary column. Determination of methylmercury is commonly done via distillation, aqueous ethylation, purge, and trap gas chromatography CV-AFS (cold vapor atomic fluorescence spectroscopy). In this lab, instead of distillation, we use direct ethylation using a published method (Mansfield and Black, 2015) to good effect. The 2700 is extremely senstive and can measure Hg species concentrations down to 0.002 ng/L. The 2700 teams up with the 2600 in our Class 10,000 cleanroom, sharing an autosampler.

Elemental concentrations in liquids

The “jewel in the crown” of the BiCycles Lab. We’re pleased to be one of the first labs to operate a multi-quadrupole NexION 5000 (or ICP-MS/MS). Inductively Coupled Plasma Mass Spectrometry is one of the most sensitive techniques for elemental concentration analysis in liquid samples. Many elements on the periodic table (including previously “difficult to analyze” elements) can be measured down to sub-ppt levels. This “next generation” of ICP-MS/MS instruments are now able to measure isotope ratios at relatively high precision. Our lab are generating methods for Li, Sr and Pb isotope ratios in natural waters (contact Jack Murphy for more details).

Our NexION 5000 is equipped with HN3, N2O, O2, and He reaction/collision gases for best-in-class polyatomic interference removal. The instrument is equipped with Pt-tipped cones for ultimate sensitivity. Coupled to the NexION 5000 is an ESI DXCi autocorrecting autosampler, with SampleSense for fast uptake and rinsing, and an enclosure to protect sensitive samples. The DXCi currently has  capacity for 160 samples and standards. Typical sample uptake for ca. 50 elements across 3 modes (standard, DRC-NH3, DRC-O2) is ~1 to ~1.5 mL.

The NexION 5000 is housed in our Class 10,000 cleanroom with a dedicated Class 100 flow hood for critical sample prep.