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Working Standards for d18O
measurements
|
Working Standard |
d18O vs VSMOW (‰) |
Std Error (‰)* |
| 18Onearzero+ |
4.09 |
0.07 |
| PNZ |
-6.6 |
0.07 |
| Dasani+ |
-7.99 |
0.06 |
| MSW |
-14.5 |
0.08 |
| DMSW |
-23.3 |
0.06 |
| DSW-ANT |
-33.5 |
0.05 |
| ANT+ |
-49.70 |
0.04 |
*n = 7 to 9
+ calibrated in 2005
The raw data for the 18O working standard calibrations is
here in excel format. No drift was
observed here so no drift correction was performed on this data. If you use the
raw data in the second worksheet then you can
recalculate the
values for the standards and check them against the ones shown in the table
above. If you have questions about how to go through the data, please feel free
to contact the lab manager.
Working Standards for d2H
measurements:
|
Working Standard |
d2H vs VSMOW (‰) |
Std Error (‰)* |
| 2Hnearzero+ |
-5.5 |
0.4 |
| PNZ |
-37.4 |
0.4 |
| Dasani+ |
-63.7 |
0.3 |
| MSW |
-108.0 |
0.3 |
| DMSW |
-136.6 |
0.2 |
| DSW-ANT |
-256.2 |
0.2 |
| ANT+ |
-393.5 |
0.5 |
*n = 7 to 9
+ calibrated in 2005
All working standards are calibrated against VSMOW and SLAP. GISP is run with
the calibration as an accuracy check.
The raw data for the 2H working standard calibrations is
here in excel format. It seems that we
didn't do so great a job sealing some of these vials as several apparently had
no H2 in them. A drift correction was used here but drift was
insignificant in the end. The precision of the measurements was slightly
improved with the drift correction, however, it did not change the actual final
measured values. If you use the raw data in the second worksheet then you can
recalculate the
values for the standards and check them against the ones shown in the table
above. If you have questions about how to go through the data, please feel free
to contact the lab manager.
Working standards are stored in amber 240mL Qorpak bottles with the polyseal
cap. When a new working standard bottle is opened for use, the entire contents
is transferred to 5mL glass ampoules in 5mL aliquots and flame sealed. For any given
analysis multiple working standards are used (two to
bracket the samples and at least one with a midway value as a check of
measurement accuracy and precision). The
working standards are spread throughout the sequence so as to minimize effects
of instrumental drift.
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Page last updated: June 19, 2007
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