Zaidin Stable Isotope Mass Spectrometry Facilities

Staff:

Dr. Emilio Reyes (Laboratory and Services Director)

emilio.reyes@eez.csic.es

The stable isotope facilities at Estacion Experimental del Zaidin (Granada, Spain) is equipped with a Finnigan MAT 251 gas isotope ratio mass spectrometer capable of running carbon dioxide, hydrogen, sulfur dioxide, and nitrogen dioxide. Geologic and water samples are prepared for isotopic analysis with vacuum extraction lines. The laboratory presently has two carbonate lines, a silicate fluorination line, a uranium reduction line (for D/H), a CO₂-H₂O equilibration line, zinc reduction line (for D/H), and recently an Elemental Analyzer has been attached to measure C and N in organic samples. Click here for some pictures of the lab.

Lab Capabilities

The Zaidin stable isotope laboratory is equipped with vacuum extraction lines and other apparatus required to prepare water and a variety of geologic and biologic materials for isotopic analysis. We can analyze the following:

Geological Materials

Carbonates

Carbonate rocks, minerals, and cements are reacted with 100% phosphoric acid, and the evolved CO₂ gas is analyzed mass spectrometrically for carbon and oxygen isotopic composition.

Silicates, Oxides and Phosphates

Silicate rocks, mineral separates, oxide mineral separates and phosphates are reacted with chlorine trifluoride (ClF₃) at elevated temperature to liberate molecular oxygen. Subsequent reaction with a hot carbon rod converts the evolved oxygen to CO₂ gas which may be analyzed on the mass spectrometer. In the case of phosphates an arduous pretreatment is needed to transform the sample into silver phosphate or bismuth phosphate.

Water Samples

D/H measurements via uranium reduction

The uranium reduction line is used to extract hydrogen from water for D/H measurements. Our uranium line is equipped with an online fluid inclusion decrepitation furnace for D/H measurements of microquantities of H₂O, and deshidroxylation of clay minerals. Waters are reacted with depleted uranium at elevated temperatures to produce uranium oxide and hydrogen gas. The resulting gas is collected with a Toeppler pump and analyzed on the mass spectrometer.

D/H measurement via zinc reduction

Analogous to the uranium reduction procedure, water samples are reacted at elevated temperatures with Zn metal to produce hydrogen gas and zinc oxide. Since the supply of Analar Zinc is exhausted we use is produced at Indiana University this contains a special contaminant that seems to be ideal for catalyzing the water-zinc reaction.

Oxygen isotope analysis

The Zaidin stable isotope laboratory can analyze both micro- (e.g. fluid inclusion) and macro-quantities of H₂O for oxygen isotopic composition, however, at the moment we are only using the macro-quantitites method and in the future we are planning to add the micro-one (Guanidine Hidrocloride method). The method for macro-quantities of water is achieved by isotopically equilibrating a known amount of carbon dioxide with a known amount of water in a warm shaker bath, and then re-extracting the CO₂ for isotopic measurement. The initial isotopic composition of the water sample may then be back-calculated using an isotope mass balance relationship.

Biological and Geological materials

Carbon and Nitrogen Analysis in Organic Matter

We use a micro-Dumas combustion elemental analyzer (Fison NA1500 NC) to convert biological materials including leaves, roots and other solid and liquid substances, into the simple gases N₂ and CO₂ that are then introduced into the mass spectrometer where the stable isotope ratios are measured. We can also measure the isotopes in biological samples such as plasma, urine, aminoacids, saliva, breath and others, all of them related with biologic research or clinical analysis (protein synthesis measurement, energy expenditure, or breath test for example). If the sample can not be combusted then a vacuum extraction lines technique can be used (N-15 using the Rittenberg method, for example).

Research and Services

Our lab is involved in a variety of proyects, principaly, those related with ore deposits, paleoclimatology, sedimentology, hidrology and mineral syntesis. We have collaborations with researchers from other universities, national laboratories including commercial companies and can supply an analysis service. We strongly recomend to contact Dr. Reyes to know which of these analysis are being currently offered like services and which like research projects only.

Correspondence

Dr. Emilio Reyes

Dept. of Earth Sciences and Environmental Chemistry

Stable isotope biogeochemistry group

Estacion Experimental del Zaidin (CSIC)

Profesor Albareda 1, 18008 Granada, Spain

phone: (34) 958 121011

fax: (34) 958 129600

Links to Internet Mass Spectrometry Resources

Want to find out more about mass spectrometry resources on the net? Murray's mass spectrometry page

Visit Finnigan Corporation's homepage for technical specifications on any of their fine products.

rafael.nugnez@eez.csic.es