Information on Batches of CO₂ in Seawater Reference Material

These reference materials were prepared at the Scripps Institution of Oceanography of the University of California, San Diego with support from the US National Science Foundation and (in the early years) from the US Department of Energy. For detailed information about an individual batch click its link to obtain a PDF copy of the batch certificate. Contact co2crms@ucsd.edu for information about the availability of such reference materials.

Batch Number	Bottling Date	Salinity	Total CO2 micromol/kg	Total Alkalinity micromol/kg	NB
Batch 01	Jan 29, 1990	33.508	2020.15	-	-
Batch 02	Oct 01, 1990	33.363	1978.70	2248.27	A
Batch 03	Jan 08, 1991	batch not stable			B
Batch 04	Mar 20, 1991	batch not stable			B
Batch 05	May 07, 1991	batch not stable			B
Batch 06	May 22, 1991	38.43	2304.64	2375.61	A,C
Batch 07	Aug 08, 1991	37.12	1926.63	-	C,D
Batch 08	Aug 26, 1991	batch not stable			B
Batch 09	Sep 20, 1991	batch not stable			B
Batch 10	Nov 15, 1991	34.572	1960.61	2257.50	A
Batch 11	Jan 07, 1992	38.50	2188.89	-	C,D
Batch 12	Feb 27, 1992	33.494	1984.26	2226.56	A
Batch 13	Jun 25, 1992	32.864	2015.13	2203.79	A
Batch 14	Jul 23, 1992	not distributed as RM			E
Batch 15	Nov 30, 1992	33.199	2031.65	2202.38	A
Batch 16	Dec 04, 1992	33.203	2034.54	2206.78	A
Batch 17	Apr 08, 1993	33.226	2044.54	2219.15	A
Batch 18	Sep 10, 1993	35.298	2115.15	2297.77	A
Batch 19	Sep 15, 1993	33.705	2004.08	-	D
Batch 20	Nov 23, 1993	33.145	1983.40	2211.53	A
Batch 21	Jan 28, 1994	34.534	1991.98	2258.36	A
Batch 22	Apr 01, 1994	33.561	1995.19	2217.16	A
Batch 23	May 04, 1994	33.483	1993.10	2212.71	A
Batch 24	Aug 26, 1994	33.264	1987.53	2215.51	A
Batch 25	Nov 10, 1994	34.910	2127.21	2299.79	A,F
Batch 26	Dec 13, 1994	33.258	1978.34	2176.59	A
Batch 27	Dec 21, 1994	33.209	1988.10	2214.89	A
Batch 28	Feb 27, 1995	33.407	1994.64	2223.47	A
Batch 29	Apr 19, 1995	33.701	1902.33	2184.76	A
Batch 30	Jun 14, 1995	33.420	1988.78	2201.88	A
Batch 31	Aug 16, 1995	32.899	1876.57	2130.33	A
Batch 32	Oct 17, 1995	33.745	1997.57	2221.48	A
Batch 33	Feb 27, 1996	33.781	2009.85	2234.92	-
Batch 34	Apr 23, 1996	34.514	2061.52	2284.35	-
Batch 35	Aug 06, 1996	35.661	2111.62	2354.05	-
Batch 36	Nov 07, 1996	35.368	2050.21	2283.83	-
Batch 37	Apr 02, 1997	34.983	2044.15	2314.11	-
Batch 38	May 08, 1997	34.932	2089.99	2300.89	-
Batch 39	Jul 24, 1997	batch not stable			B
Batch 40	Sep 16, 1997	33.383	1985.76	2196.41	-
Batch 41	Oct 31, 1997	33.368	1977.71	2195.78	-
Batch 42	Dec 16, 1997	33.364	1985.10	2210.54	-
Batch 43	Mar 25, 1998	33.598	1988.64	2202.86	-
Batch 44	May 18, 1998	34.271	2030.66	2258.24	-
Batch 45	Aug 19, 1998	33.487	1994.17	2204.38	-
Batch 46	Oct 27, 1998	33.769	1992.92	2191.27	-
Batch 47	Jan 26, 1999	33.716	2006.61	2227.93	-
Batch 48	May 14, 1999	33.442	1999.91	2189.62	G
Batch 49	Oct 07, 1999	33.935	1991.14	2172.06	G
Batch 50	Jan 21, 2000	33.411	2006.21	2211.11	G
Batch 51	Jun 08, 2000	34.217	2050.28	2269.86	G
Batch 52	Aug 23, 2000	33.608	2005.57	2224.72	G
Batch 53	Dec 13, 2000	33.453	2012.03	2222.68	G
Batch 54	Apr 20, 2001	35.228	2107.35	2342.09	G
Batch 55	May 15, 2001	33.506	2012.06	2227.85	G
Batch 56	Sep 14, 2001	33.408	2014.16	2219.69	G,H
Batch 57	Nov 29, 2001	33.485	2005.98	2230.33	G
Batch 58	Feb 20, 2002	33.487	2010.94	2223.66	G
Batch 59	May 3, 2002	33.316	2007.10	2220.98	G
Batch 60	Aug 30, 2002	33.012	1991.24	2199.55	G
Batch 61	Jun 23, 2003	33.076	1998.17	2202.04	G
Batch 62	Aug 21, 2003	35.224	2126.46	2338.20	G
Batch 63	Dec 12, 2003	33.369	2016.02	2222.27	G
Batch 64	Jan 15, 2004	37.339	2090.89	2427.60	G
Batch 65	Feb 20, 2004	33.049	1993.68	2206.00	G
Batch 66	Jul 23, 2004	32.962	1969.57	2193.27	G
Batch 67	Oct 15, 2004	34.411	1983.75	2258.27	G
Batch 68	Dec 10, 2004	33.758	2003.78	2233.71	G
Batch 69	Jan 4, 2005	31.569	1907.63	2114.42	G
Batch 70	Apr 27, 2005	33.016	1989.53	2160.46	G
Batch 71	May 19, 2005	33.923	2032.84	2254.50	G
Batch 72	Jul 27, 2005	35.015	2091.61	2312.79	G
Batch 73	Nov 17, 2005	34.523	2057.30	2253.50	G
Batch 74	Dec 15, 2005	34.739	2085.53	2305.34	G
Batch 75	Mar 2, 2006	33.222	2005.98	2210.09	G
Batch 76	May 18, 2006	34.835	2101.69	2314.49	G
Batch 77	July 13, 2006	33.129	1998.44	2199.33	G
Batch 78	September 21, 2006	33.285	1991.93	2185.57	G
Batch 79	November 21, 2006	34.236	2038.63	2262.31	G
Batch 80	January 9, 2007	33.357	2006.50	2214.49	G
Batch 81	April 26, 2007	33.378	2011.49	2201.20	G
Batch 82	June 28, 2007	35.356	2118.25	2335.02	G
Batch 83	July 26, 2007	34.611	2055.57	2286.34	G
Batch 84	September 6, 2007	33.391	2001.23	2201.01	G
Batch 85	October 12, 2007	33.326	2000.44	2184.03	G
Batch 86	December 20, 2007	33.097	1998.37	2175.56	G
Batch 87	April 15, 2008	33.191	2012.01	2201.16	G
Batch 88	June 5, 2008	33.328	2013.42	2205.41	G
Batch 89	July 17, 2008	33.494	2025.71	2214.06	G
Batch 90	September 5, 2008	33.390	1985.61	2216.00	G
Batch 91	October 10, 2008	33.397	2011.61	2182.90	G
Batch 92	November 7, 2008	33.321	1996.35	2201.91	G
Batch 93	December 18, 2008	33.615	2020.34	2230.06	G
Batch 94	January 30, 2009	33.424	2015.92	2222.39	G
Batch 95	March 2, 2009	33.300	2016.38	2217.51	G
Batch 96	May 8, 2009	33.081	2005.36	2212.40	G
Batch 97	June 26, 2009	33.142	2003.03	2211.21	G
Batch 98	August 31, 2009	33.366	2013.85	2231.11	G
Batch 99	October 9, 2009	35.185	2115.04	2356.78	G
Batch 100	November 13, 2009	33.351	2021.65	2232.36	G
Batch 101	January 15, 2010	33.590	2027.80	2241.44	G
Batch 102	February 19, 2010	33.310	2012.24	2227.46	G
Batch 103	April 9, 2010	33.498	2023.23	2232.94	G
Batch 104	June 11, 2010	33.300	2020.10	2222.61	G
Batch 105	July 23, 2010	33.504	2036.72	2235.16	G
Batch 106	September 10, 2010	33.274	2004.90	2219.68	G
Batch 107	October 8, 2010	32.985	1995.12	2205.17	G
Batch 108	November 10, 2010	33.224	2022.70	2218.00	G
Batch 109	December 9, 2010	33.328	2026.33	2224.26	G
Batch 110	January 14, 2011	33.418	2018.28	2229.04	G
Batch 111	February 18, 2011	33.264	2045.66	2222.80	G
Batch 112	June 3, 2011	33.305	2011.09	2223.26	G
Batch 113	July 8, 2011	33.357	2016.68	2224.65	G
Batch 114	August 19, 2011	33.208	2000.93	2217.91	G
Batch 115	September 16, 2011	33.572	2007.45	2242.84	G
Batch 116	October 14, 2011	33.451	2014.18	2232.76	G
Batch 117	November 10, 2011	33.503	2009.99	2239.18	G
Batch 118	December 16, 2011	33.377	2013.33	2229.75	G
Batch 119	January 20, 2012	33.263	2014.78	2221.24	G
Batch 120	February 24, 2012	33.072	2002.61	2208.43	G
Batch 121	April 6, 2012	33.346	2039.26	2225.01	G
Batch 122	May 11, 2012	33.435	2042.29	2233.32	G
Batch 123	August 16, 2012	33.384	2022.04	2225.21	G
Batch 124	October 12, 2012	33.190	2015.72	2215.08	G
Batch 125	November 6, 2012	33.186	2141.94	2216.26	G
Batch 126	December 7, 2012	33.460	2007.64	2232.55	G
Batch 127	January 18, 2013	33.424	2023.30	2228.64	G
Batch 128	February 15, 2013	33.442	2013.54	2240.28	G
Batch 129	April 26, 2013	33.361	2016.65	2237.32	G
Batch 130	May 24, 2013	33.661	2072.58	2238.04	G
Batch 131	June 28, 2013	33.621	2028.99	2241.35	G
Batch 132	July 26, 2013	33.441	2032.65	2229.24	G
Batch 133	August 30, 2013	33.341	2021.12	2224.37	G
Batch 134	September 27, 2013	33.651	2026.91	2236.51	G
Batch 135	November 1, 2013	33.561	2036.96	2226.33	G
Batch 136	December 6, 2013	33.678	2021.15	2246.74	G
Batch 137	January 17, 2014	33.607	2031.90	2231.59	G
Batch 138	February 21, 2014	33.398	2033.98	2221.75	G
Batch 139	March 27, 2014	33.267	2023.23	2250.82	G
Batch 140	May 2, 2014	33.471	2040.94	2232.58	G
Batch 141	June 13, 2014	33.417	2033.26	2234.07	G
Batch 142	July 25, 2014	33.389	2038.07	2227.59	G
Batch 143	August 29, 2014	33.620	2017.75	2241.04	G
Batch 144	October 10, 2014	33.571	2031.53	2238.60	G
Batch 145	December 4, 2014	33.409	2034.13	2226.16	G
Batch 146	January 30, 2015	33.122	2002.92	2214.11	G
Batch 147	March 13, 2015	33.427	2014.52	2231.39	G
Batch 148	May 1, 2015	33.624	2024.12	2241.13	G
Batch 149	June 12, 2015	33.331	2011.67	2224.69	G
Batch 150	July 31, 2015	33.343	2017.88	2214.71	G
Batch 151	September 4, 2015	33.345	2033.83	2225.56	G
Batch 152	October 23, 2015	33.371	2020.88	2216.94	G
Batch 153	December 4, 2015	33.357	2017.95	2225.59	G
Batch 154	January 22, 2016	33.347	2037.68	2224.30	G
Batch 155	March 4, 2016	33.506	2042.75	2235.07	G
Batch 156	April 8, 2016	33.455	2052.72	2236.51	G
Batch 157	May 20, 2016	33.463	2049.43	2229.82	G
Batch 158	June 17, 2016	33.516	2043.54	2226.55	G
Batch 159	July 22, 2016	33.572	2027.14	2213.59	G
Batch 160	September 9, 2016	33.414	2030.39	2212.44	G
Batch 161	October 14, 2016	33.356	2037.38	2207.33	G
Batch 162	November 18, 2016	33.312	2177.27	2403.72	G
Batch 163	January 13, 2017	33.362	2039.43	2215.34	G
Batch 164	February 17, 2017	33.247	2238.89	2309.32	G
Batch 165	April 14, 2017	33.329	2064.41	2214.09	G
Batch 166	May 12 , 2017	33.477	2053.48	2212.56	G
Batch 168	June 30, 2017	33.481	2071.47	2207.62	G
Batch 169	August 4, 2017	33.518	2063.31	2207.03	G
Batch 170	September 8, 2017	33.573	1982.42	2198.77	G
Batch 171	October 13, 2017	33.434	2029.19	2217.40	G
Batch 172	November 17, 2017	33.450	2038.99	2217.40	G
Batch 173	December 8, 2017	33.414	2042.41	2210.77	G
Batch 174	January 26, 2018	33.408	2050.56	2212.23	G
Batch 175	March 16, 2018	33.458	2067.06	2224.53	G
Batch 176	May 4, 2018	33.532	2024.22	2226.38	G
Batch 177	June 15, 2018	33.641	2067.67	2223.89	G
Batch 178	July 20, 2018	33.782	1952.65	2216.53	G
Batch 179	September 7, 2018	33.841	1941.92	2219.26	G
Batch 180	October 19, 2018	33.623	2021.87	2224.47	G
Batch 181	December 14, 2018	33.582	2030.77	2222.71	G
Batch 182	January 25, 2019	33.465	2039.10	2230.91	G
Batch 183	March 1, 2019	33.420	2040.25	2230.52	G
Batch 184	April 12, 2019	33.290	2052.75	2226.44	G
Batch 185	May 24, 2019	33.418	2029.88	2220.67	G
Batch 186	June 28, 2019	33.525	2012.59	2212.00	G
Batch 187	August 2, 2019	33.602	2002.85	2204.98	G
Batch 188	September 27, 2019	33.595	2099.26	2264.96	G
Batch 189	November 1, 2019	33.494	2009.48	2205.26	G
Batch 190	December 20, 2019	33.459	2033.86	2218.31	G
Batch 191	February 14, 2020	33.316	2051.40	2225.50	G
Batch 192	January 14, 2021	33.518	2070.83	2213.68	G
Batch 193	February 24, 2021	33.425	2048.36	2193.07	G
Batch 194	March 24, 2021	33.361	2025.17	2169.83	G
Batch 195	April 22, 2021	33.485	2024.96	2213.51	G
Batch 196	May 20, 2021	33.519	2018.83	2215.32	G
Batch 197	June 18, 2021	33.529	2115.23	2256.77	G
Batch 198	July 5, 2021	33.504	2033.64	2200.67	G
Batch 199	October 24, 2021	33.473	2021.66	2202.75	G
Batch 200	December 2, 2021	33.464	2022.46	2186.43	G
Batch 201	January 28, 2022	33.302	2048.19	2207.56	G
Batch 202	March 18, 2022	33.356	2043.33	2215.13	G
Batch 203	May 20, 2022	33.464	2029.92	2214.54	G
Batch 204	July 22, 2022	33.494	2028.23	2202.12	G
Batch 205	September 9, 2022	33.443	2011.85	2202.05	G
Batch 206	November 22, 2022	33.423	2021.55	2193.88	G
Batch 207	January 13, 2023	33.237	2040.33	2199.32	G
Batch 208	February 24, 2023	33.140	2059.66	2215.76	G
Batch 209	April 7, 2023	33.147	2060.05	2210.40	G
Batch 210	May 19, 2023	33.231	2046.37	2220.62	G
Batch 211	June 6, 2023	33.272	2057.02	2218.40	G
Batch 212	August 10, 2023	33.341	2023.82	2193.54	G
Batch 213	September 22, 2023	33.232	2024.67	2203.56	G
Batch 214	December 01, 2023	33.075	2014.53	2200.67	G
Batch 215	February 16, 2024	32.942	2024.29	2191.30	G
Batch 216	March 22, 2024	32.899	2029.63	2188.02	G

* PROVISIONAL VALUES.

(A) Total alkalinity was not measured when the batch was originally certified; the total alkalinity value is based on measurements performed on archived samples of the batch.

(B) The measured values of total dissolved inorganic carbon and of total alkalinity changed with time, probably due to the effects of microbial growth in the bottles. This batch was not certified as reference materials.

(C) This batch was a synthetic solution of sodium bicarbonate in sodium chloride prepared directly in the holding tank by diluting concentrated, filtered solutions of the two salts with deionized (Milli-Q®) water. The salinity value was assigned so as to allow the correct density at 20^oC to be calculated using the density-salinity relationship for sea water.

(D) Total alkalinity was not measured as archived samples were not available; value is expected to have been stable.

(E) This batch was used as a basis of a collaborative study for the analysis of total dissolved inorganic carbon by coulometry.

(F) This batch was prepared in England by using North Atlantic near surface water. All analyses were performed, as with all previous batches, in the laboratories of Andrew G. Dickson and Charles D. Keeling.

(G) This batch was certified for total dissolved inorganic carbon using a Ruska electronic constant-volume manometer rather than the mercury column manometer for Batches 1 - 47.

(H) This batch was used in a collaborative study involving the analysis of CO₂ in air from glass ampoules.