Astoria-Pacific nutrient analyzer

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.