Dalhousie University - Inspiring Minds






Thermo Delta V IRMS - d15N on nitrates, nitrites, and ammonia

This instrument is coupled with a Conflo lll and Precon for nitrogen isotopic composition of nitrate and nitrite of seawater

This method mainly consists of the reduction of nitrate to nitrite using spongy cadmium followed by reduction to nitrous oxide using sodium azide in an acetic acid buffer. The nitrous oxide is purged from the samples and cryogenically trapped using a modified Isomass Precon system. The isolated nitrous oxide is then analyzed on a Thermo Scientific Delta V continuous flow isotope ratio mass spectrometer.   

Picarro L2130-i Water Isotope Analyzer - d18O and d2D

Freshwater and seawater samples are analyzed on this Picarro water isotope analyzer. One ul of water is injected, vaporized and introduced into the analyzer where readings of d18O and d2D are obtained using the cavity ring down spectrometry (CRDS) technique.


Isoprime 100 IRMS - d15N and d13C in bulk organic and inorganic of solid samples 

Filtered seawater samples or sediment samples are packed in tin capsules to obtain 80 ug N. The Vario Micro Cube is configured to run in CN mode and calibrated to obtain quantitative %C and %N. The technique consists of flash combusting samples at 1150˚C, reducing nitrogen and carbon compounds to N2 and CO2 products and separating the different elements with a temperature programmed desorption trap. These different gaseous components are then carried by ultrapure helium to the Isoprime 100 continuous flow isotope ratio mass spectrometer for d15N and d13C analysis.

Guildline 8410A Salinometer

Only 100 ml of a saltwater sample is required to measure salinity using conductivity.


Skalar SAN++ Continuous Flow Nutrient Analyzer

This automated, continuous flow, analysis measures Nitrite, Nitrate, Phosphate, Silicate, and Ammonia. Chemical reagents and samples, segmented with air bubbles, are pumped through a manifold to undergo treatment such as mixing, heating, etc. before entering a flow cell to be detected with either colorimetric detection (with optical background correction) or a fluorometer (Ammonia).

Agilent 7890B Gas Chromatograph - Mass Spectrometer 5977A - Halocarbon gases concentrations

Volatile halocarbons, such as methyl iodide (CH3I), are purged and trapped on an IMT VSP4000 system, then the isolated compounds are carried to a gas chromatograph (GC) equipped with a micro electron capture detector (ECD) and a mass spectrometer. This instrument measures methyl idodie (CH3I), chloriodomethan (CH2ClI), diiodomethan (CH2I2), dibrommethan (CH2Br2) and bromoform (CHBr3).

Apollo acidification system coupled to a Picarro G2201-i analyzer for DIC-d13C analysis

Four ml of sample is transferred to a cooled chamber where phosphoric acid is added for transformation of dissolved inorganic carbon to CO2 gas, which is then sparged and sent to the Picarro analyzer for analysis of carbon isotopic composition (d13C) as well as quantitative determination of dissolved inorganic carbon (DIC (uM.l-1)).

Agilent 7890B Series Gas Chromatograph coupled to an Agilent 7697A Headspace Sampler for nitrous oxide (N2O) in water

A heaspace is created by gently displacing 10 ml of water by ultra-pure helium in a 20 ml vial. The sample is shaken for 10 min and placed in the headspace sampler for 15 min for gas equilibration at 40 C.  The gas then goes through a 1 ml loop and is transferred to a gas chromatograph equipped with an electron capture detector (GC-ECD) for nitrous oxide measurement.  

Methods Under Development

Picarro G5131-i Analyzer - nitrous oxide isotopes and concentration