GISP2 Extraction methods for nitrogen and oxygen isotopes

REFERENCE:

Sowers, T., E.J. Brook, D. Etheridge, T. Blunier, A. Fuchs, M.C.
Leuenberger, J.A. Chappellaz, J.M. Barnola, M. Wahlen, B. Deck, and C.
Weyhenmeyer. 1997. An interlaboratory comparison of techniques for
extracting and analyzing trapped gases in ice cores. Journal of Geophysical
Research 102:26527-26538.

DATA DESCRIPTION:

The columns (1-7) are as follows:
Column #1 URI (University of Rhode Island) sample ID numbers.
Column #2 Exact depth in meters below the surface.
Column #3 the delta 15N of trapped N2 with respect to (wrt) modern air.
Column #4 the delta 18O of trapped O2 wrt modern air (measured values)
Column #5 the delta O2/N2 of trapped air wrt modern (corrected for gravitational fractionation).
Column #6 the delta CO2/N2 of trapped air wrt modern (corrected for gravitational fractionation).
Column #7 the delta 18O of paleoatmospheric air wrt modern (corrected for gravitational fractionation).


DATA:
                  CORRECTED VALUES RELATIVE TO PRESENT DAY AIR          
                  Values are in per mil units                                    
Sample ID	midpoint depth (m)	15N	18O	32/28	44/28	18Oatm

SAMPLES WHICH WERE EXTRACTED IN GREENLAND AND TRANSFERED TO 						
AMPOULES                                              						
72.9#1	72.9	0.27	0.69	-7.9	187.7	0.15
72.9#2	72.9	0.28	0.67	-7.9	227.9	0.11
75.4#1	75.4	0.32	0.77	-17.7	216.5	0.14
75.4#2	75.4	0.37	0.72	-17	223.6	-0.03
78.3#2	78.3	0.34	0.66	-8.6	200.5	-0.02
80.9#1	80.9	0.37	0.75	-17.8	501.4	0
84#1	84.2	0.36	0.74	-4.9	249.4	0.03
84.6#1	84.6	0.33	0.71	-9	180.5	0.04
105.1#1	105.1	0.34	0.64	-2.8	22.1	-0.03
105.1#2	105.1	0.27	0.62	-4.6	0.09	
125.0#1	125	0.26	0.66	-6.6	100.3	0.14
125.0#2	125	0.3	0.77	-6.9	64.4	0.16
145.4#1	145.4	0.25	0.62	-2.8	-17.3	0.13
145.4#2	145.4	0.24	0.6	-3.3	2.6	0.11
164#1	164.1	0.31	0.66	-11.4	32.6	0.05

Samples which were analyzed at URI after 3 months of storage                     						

72.95#1	72.9	0.28	0.65	-9.7	429.5	0.09
72.95#2	72.9	0.3	0.63	-12.1	428.8	0.03
78.3#1	78.3	0.3	0.65	-9.4	378.7	0.05
78.3#2	78.3	0.33	0.68	-11.4	501.8	0.02
80.8#1	80.9	0.29	0.6	-10.7	364.2	0.02
80.8#2	80.9	0.3	0.66	-9.9	354.7	0.05
84.7#1	84.6	0.33	0.69	-11.2	518.3	0.03
84.7#2	84.6	0.36	0.62	-10.6	783.5	-0.11
105.1#1	105.1	0.34	0.75	-1.1	60.5	0.07
105.1#2	105.1	0.29	0.63	-0.6	156.9	0.06
125.0#1	125	0.33	0.63	-4.9	593.3	-0.03
125.0#2	125	0.31	0.57	-5.9	194.1	-0.06
145.4#1	145.4	0.31	0.61	-7.7	413.1	0
145.4#2	145.4	0.3	0.66	-15.7	322.6	0.05
164.1#1	164.1	0.31	0.62	-1.6	449.2	0.01
164.1#2	164.1	0.3	0.59	-1.2	120.4	0
197.5#1	197.5	0.33	0.56	1.6	161.6	-0.1
197.5#2	197.5	0.3	0.58	1.8	112.1	-0.01

Samples which were analyzed at URI after 7 months of storage                     						

73#1	72.9	0.31	0.58	-17.4	638.3	-0.03
73#1	72.9	0.31	0.58	-17.4	638.3	-0.03
78#1	78.3	0.29	0.68	-9.4	544.3	0.09
78#2	78.3	0.29	0.64	-10.9	381.4	0.06
80.9#2	80.9	0.33	0.67	-11	550.1	0.01
84.7#1	84.6	0.32	0.68	-4.4	389.4	0.05
84.7#2	84.6	0.36	0.61	-3.1	245.3	-0.1
105#1	105.1	0.26	0.56	-11.2	232.7	0.04
105#2	105.1	0.23	0.62	-11.2	210.5	0.16
125#1	125	0.27	0.63	-6.6	262	0.09
125#2	125	0.28	0.56	-4.6	43.8	0
145#1	145.4	0.28	0.73	-2.8	64.8	0.17
145#2	145.4	0.28	0.58	-3.1	99.3	0.02
164#1	164.1	0.29	0.68	-1.9	90.4	0.1
164#2	164.1	0.3	0.72	-2.5	118.8	0.11
197#2	197.5	0.3	0.59	0.4	47.2	0

Other samples run at various times here at URI to check extraction procedure						

94.2	94.2	0.27	0.68	-4.5	206	0.14
149	149	0.32	0.67	-4	0.03	
149	149	0.29	0.69	-3.1	0.11	
149	149	0.24	0.64	-2.4	0.15	
149	149	0.3	0.64	-3.5	0.04	
149	149	0.28	0.64	-3	0.08	
149	149	0.24	0.49	-5.3	0	
149	149	0.27	0.59	1.3	0.05	
149	149	0.27	0.6	-2.7	0.06	
149	149	0.28	0.63	-2.9	0.06	
149	149	0.28	0.69	-3.5	0.14	
149	149	0.24	0.67	-3.9	0.19	
149	149	0.27	0.59	-3.6	0.05	
154.2A	154.2	0.32	0.64	-3.2	-33	-0.01
154.2B	154.2	0.3	0.66	-3.6	285	0.05
174.2A	174.2	0.32	0.73	-10	529	0.08
174.2B	174.2	0.31	0.7	-5.8	272	0.08
194.2A	194.2	0.33	0.65	-12.9	433	0
194.2	194.2	0.3	0.74	-13.2	-24.8	0.15
194.2	194.2	0.28	0.73	-4	63	0.17
214.3A	214.3	0.36	0.72	-9.2	201	-0.01
214.3B	214.3	0.32	0.69	-5	181	0.04
234.2A	234.2	0.33	0.71	-10.9	688	0.06
234.2B	234.2	0.33	0.75	-8.3	652	0.08
254.2A	254.2	0.29	0.67	-4.6	364	0.1
254.2B	254.2	0.3	0.63	-2.4	104	0.03
254.2B	254.2	0.31	0.63	-1.9	-30	0.01
274.2A	274.2	0.31	0.72	-4.4	295	0.1
274.2B	274.2	0.3	0.72	-8	159	0.13
274.2B	274.2	0.33	0.74	-9.1	457	0.09
294.2A	294.2	0.31	0.71	-11.2	461	0.09
294.2B	294.2	0.29	0.66	-9.9	-35	0.08
314.2A	314.2	0.33	0.79	-12.7	356	0.14
334.2	334.2	0.29	0.66	-7.2	200	0.08
334.2	334.2	0.29	0.66	-7.6	291	0.09
334.2	334.2	0.33	0.87	-22.5	1015	0.21
334.2	334.2	0.3	0.65	-9.4	249	0.06