18 O & D/H Analysis of Solids by TC/EA-IRMS

1. 18O & D/H Analysis of Solids by TC/EA-IRMS

2. Collect your samples

3. Sample Preparation • Material needs to be dry and homogenous • Organisms can be analyzed wholeif small enough • Separate samples are required for hydrogen and oxygen

4. Sample Weights • Sample should contain: • 400 µg oxygen • 80 µg hydrogen

5. Encapsulating Samples Weigh samples into silver capsules The Good The Bad A crimper plate helps shape capsules The Ugly

6. Organizing Trays • Load samples across rows of 96-wells trays • Do not leave empty wells between samples • Label trays uniquely and clearly • Place samples for different analyses in different trays

7. Sealing trays • For small samples, place an index card or parafilm between tray and lid before sealing • Tape lid securely to tray – use lab tape

8. International Shipments • Use a shipping company that brokers their own packages (such as Fedex or DHL) • Customs documents • Specify plant genus and species • Specify for “chemical analysis” • Permits are required for bird feathers Email SIF@ucdavis.edufor the appropriate permit

9. Paperwork • Complete an Analysis Order Form for each analysis type • Complete a sample list for each Analysis Order From • Email forms to sif@ucdavis.edu • Include printed copies with samples

10. (3) Deflect ions (2) Focus ion beam (1) Ionize gas (4) Detect masses IRMS Basics

11. HeFlow Auto sampler CO Flow toIRMS H2 H2OTrap GCColumn CombustionReactor (1400°C) Gas separation in GC column Pyrolysis (High Temperature)TC/EA-IRMSHD & 18O in solids

12. Chromatography

13. Standards - Hydrogen • International standard (IAEA-CH-7) and inter-laboratory keratin standards are included in all runs • In-house standards have been calibrated against same standards • All results are expressed with respect to VSMOW

14. Standards - Oxygen • International standards (IAEA-601, IAEA-602, USGS-8568) are included in all runs • In-house standards have been calibrated against same standards • All results are expressed with respect to VSMOW

15. Raw Data • Reviewed in reprocessor • Poor chromatography • Evaluate reference gas values • Confirm placement of standards

16. Hydrogen Corrections • All corrections are performed on raw ratios • Memory, if needed • Drift over time • H3+ / Size correction • Scale expansion

17. Oxygen Corrections • Memory • Drift • Size • Scale expansion

18. Exchangeable hydrogen • Carboxyl and hydroxyl groups will exchange hydrogen atoms with water vapor • Results in shift of deuterium value

19. Exchangeable Hydrogen - Keratin • Accepted keratin standards allow measurement of keratin samples by “like treatment” • Standards and samples equilibrate with lab atmosphere and are analyzed together

20. Exchangeable Hydrogen - Keratin • Correcting to known values of keratin standards determines value of non-exchangeable hydrogen of keratin samples Only works for keratin

21. Exchangeable Hydrogen • For non-keratin samples, percent of exchangeable hydrogen must be calculated

22. Dual-Equilibration • By equilibrating a material with waters of different deuterium values, the percent of exchangeable hydrogen and deuterium value for the non-exchangeable fraction can be determined

23. Oxygen – Memory effect • Oxygen is prone to carryover from one sample to the next • Varies with age of reactor and ash accumulation • Can be corrected for by mass balance Best precaution – run replicates