General Info

The MSRF performs dissolved nutrient analysis on aqueous samples using an Astoria Pacific Segmented Flow Analyzer.

We are currently equipped to analyze five nutrients: ammonium, phosphate, silicate, nitrite and total nitrite+nitrate. The following table lists the methods used for each nutrient as well as our minimum detection limits (MDL) in seawater.

Nutrient	Method	Concentration range (uM)	MDL (uM)
Ammonium	A026 Rev D	0 – 40	0.10
Phosphate	A205 Rev A	0 – 10	0.02
Silicate	A221 Rev C	0 – 100	0.05
Nitrite	A182 Rev D	0 – 20	0.02
Nitrite+Nitrate	A177 Rev F	0 – 20	0.05

An example at the MSRF

The figures below illustrate a nutrient profile obtained from a CTD cast conducted on board the R/V Endeavor in June of 2016. The cast was carried out at the continental shelf break (approximately 39°46.209’N and 70°51.436’W) as part of a study examining carbon and particle fluxes down the water column.