Initial Reports, Volume 206
Ms 206IR-102
Chapter 2, Table T10. Interstitial water analyses and corresponding reproducibility.

Notes: IAPSO = International Association for the Physical Sciences of the Ocean, standard seawater. BDL = below detection limit. DOC = dissolved organic carbon. ICP-AES = inductively coupled plasma-atomic emission spectroscopy. n = number of replicate analyses.

Parameter	Method	IAPSO value accepted	IAPSO value measured	1 sigma (%)	n

Alkalinity	Gran titration	2.33	2.34	2.2	10
Cl (mM)	Titration with AgCl	559	544	0.7	12
H4 SiO4 (uM)	Spectrophotometry			0.8	5
NH4 (uM)	Spectrophotometry				
PO4 (uM)	Spectrophotometry			BDL	
SO4 (mM)	Ion chromatography	28.9	28.9	0.3	6
Mg (mM)	ICP-AES	10.55	10.63	2.1	6
Ca (mM)	ICP-AES	54	51.64	2.2	6
K (mM)	ICP-AES	10.44	10.26	4.6	6
Na (mM)	ICP-AES		465	0.4	6
Sr (uM)	ICP-AES	87	90	5.8	6
Ba (uM)	ICP-AES		70	0.6	6
B (uM)	ICP-AES	416	546	2.9	6
Li (uM)	ICP-AES	27	21	5.4	6
Mn (uM)	ICP-AES	0	0.6	2.6	6
Fe (uM) 	ICP-AES	0	BDL	BDL	
DOC (mM)	Gas chromatography			9.6	3