marum - Interstitial pore waters (IW)

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Initial sampling and analyses

Interstitial pore waters (IW)

In case of soft sediment recovery interstitial waters for geochemical analysis samples are generated from the whole round samples removed from suitable material on the catwalk. In less consolidated sediments at the top of a borehole, IW samples are generally 5 cm long (176 cc). The size of the sample may be increased as the sediment becomes more lithified with depth. The SAC and the geochemists work together to come up with an IW sampling plan that best meets the needs of the shipboard party. The IW sample may be recorded at the core entry computer via offshore DIS.

Right: ESO clean lab container during Exp. 313 New Jersey Shallow Shelf.

IODP pore water sample splits

Parameter	Seqence	Amount	Unit	Type	take with	take from	Container	Receiver	Prepare	Storage
CH4, HC	1	5	mL	sed	cut 5 mL syringe	cut face	20 mL crimp seal	10 mL saturated NaCl solution with sodium azide	receiver pipette 20mm crimper caps vials rack	shake and freeze -20° upside down
	2	a		IW	rhizon	Whole core	20/50 mL syringe		-> rhizons	cap syringe, keep cool until splitting
	2	b		IW	squeezer	5 - 10 cm WCR	20/50 mL syringe		-> squeezer	cap syringe, keep cool until splitting
pH, alkalinity	3	0.5	mL	IW	hand pipette	2 mL cup	1.5 mL Eppendorf cup		-> alkalinity titration	label and cool at 4°C
salinity	4	0.1	mL	IW	hand pipette	2 mL cup	-		-> refractometer
NH4	5	0.5	ml	IW	1 mL syringe	2 mL cup	loop		-> Ammonia detector (teflon tape gas sep.)	discard
cations	6	4	mL	IW		IW syringe	ampoule / Nalgene 4 mL	40 µL s.pure HNO3 65%	vials rack nitric acid pipette	label and keep cool at 4°C
anions	7	4	mL	IW		IW syringe	ampoule / Nalgene 4 mL		vials rack	label and keep cool at 4°C
d13C	8	1.8	mL	IW		IW syringe	1.8mL crimp vial	20 µL HgCl2 solution, no headspace!	receiver pipette 13mm crimper caps vials rack	label and keep cool at 4°C
H2S, d 34S	9	2	mL	IW	hand pipette	2 mL cup	2 mL screw cap wheaton	20 µL 50 mM Zn-acetate solution	receiver solution, vials, rack	label and keep cool at 4°C
d18O	10	1.8	mL	IW		IW syringe	1.8 mL crimp cap	no headspace !	vials rack, 13 mm crimper caps	seal cap with wax, label and keep cool at 4°C
Trace metals	11	4	mL	IW		IW syringe	Nalgene 4 mL	40 µL s.pure HNO3 65%	vials rack nitric acid pipette	label and keep cool at 4°C
DOC, PO4	12	5	mL	IW		IW syringe	ampoule		vials rack	label and keep cool at 4°C
Residual	13		mL	IW		IW syringe	20 mLGreiner / 15 mL Nalgene			label and keep cool at 4°C
Total		23.7	mL	IW