δ34S analysis of solid samples
SIBS uses a Thermo EA IsoLink CNSOH coupled to a Thermo Scientific Delta V advance stable isotope mass spectrometer in continuous flow mode.
Common sample materials are leaf, root, soil, feather, and hair.
Samples are packed in tin capsules. When the required sample size is >8mg, Vanadium pentoxide (V2O5) is added in the tin capsules. Samples are loaded in a 125-position MAS Autosampler. The reaction tube is a single tube packed with Tungsten oxide (granular 0.85 to 1.7mm) (PN B1152 from EA Consumables) and Copper wires (0.7mm) (PN 11014 from Costech). The produced SO2 gas goes through a water trap and a Rapid GC Oven. Then it goes through an open split of Conflo IV, and are analyzed by the Delta V Advantage Isotope Mass Spectrometer for the sulfur isotope ratios. An analysis of each sample takes 20 min.
Quality assurance is performed using 6 IAEA silver sulfide and barium sulfate standards (S1, S2, S3, SO-5, SO-6, NBS127). Quality control is performed using IAEA standards (S1 and NBS127) and 4 in-house plant standard (for plant samples) or 2 soil standards (for soil samples). The in-house plant and soil standards have been sent to 3 stable isotope laboratories for better evaluations of the δ34S and %S. In addition, commercially available hair standards (USGS42 and USGS43 from USGS) and low organic content soil standard (B2153 from Elemental Microanalysis Ltd.) are used for Quality control.
- Sample size: Generally ~2-8 mg for leaves (0.15-0.5 %S), 2-30mg for roots (0.05-0.5 %S), 10-40 mg for soil (depending on %S), 0.2-0.3mg for hair (4-5 %S). The minimum %S of samples we can analyze is 0.03%S. Each capsule should contain ~15ug of sulfur. The maximum sample size that fits in a tin capsule is 40mg as 40mg of V2O5 is also added in it.
- What you will receive: δ34S and %S results and Quality Assurance and Quality Control report.
- Key: Very fine, homogeneous samples. Homogenization is very important for a better accuracy and precision of your samples.
- If your samples contain small amounts of sulfur and do not produce enough peak heights for the isotope analysis, the analysis cost will be still charged to you.