Lachat nutrient analyzer
The MSRF performs dissolved nutrient analysis on aqueous samples using a QuickChem QC8500 automated ion analyzer made by Lachat.
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||Method 31-107-06-1-B||0 – 40||0.20|
|phosphate||Method 31-115-01-1-H||0 – 10||0.05|
|silicate||Method 31-114-27-1-A||0 – 100||0.10|
|nitrite||Method 31-107-05-1-A||0 – 20||0.30|
|nitrite+nitrate||Method 31-107-04-1-A||0 – 20||0.30|
An example at the MSRF
The figures below illustrate a nutrient profile obtained from a CTD cast conducted on board the RV 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.