Seawater Nutrients by FIA

Seawater AnalysisService Provided:  Analysis of seawater samples for dissolved inorganic nutrients. We also have methodologies for analysis of other aqueous samples, such as fresh waters, estuarine waters, ground waters, and neutralized digests.

Technique Used: Flow Injection Analysis, simultaneous

Concentration Range and Precision:

  Analyte Concentration Range, uM Precision
  Nitrate (NO3) + Nitrite (NO2) 0.2 - 300 +/- 0.05 or 5%
  Nitrite (NO2) 0.1 - 100 +/- 0.02 or 5%
  Phosphate (PO4) 0.1 - 200 +/- 0.02 or 5%
  Silicate (SiO4) 1.0 - 600 +/- 0.1 or 5%
  Ammonium (NH4) 0.1 - 200 +/- 0.03 or 5%

 

Sample Collection

Samples for nutrient analysis should be filtered through a 0.45um filter.  Unfiltered, turbid, or samples with widely varying concentrations within a batch of samples may require dilutions or manipulations, and are considered as ‘Other’ on the rate schedule.
 
Samples should be collected in clean, pre-rinsed glass or plastic HDPE 20ml scintillation vials. Samples being analyzed for SiO4 must be collected in plastic HDPE vials. For all other analytes, glass or plastic HDPE containers are acceptable. Some adsorption of PO4 during storage in plastic containers has been noted, so glass may be preferred if PO4 is to be determined.
 
Caps should have a plastic liner. All foil lined lids should be avoided.  
 
Storage blanks are required if NH4 is to be measured.  Storage blanks are recommended for all other analytes to detect possible contamination. 
 
A minimum of 5mL of sample is required for the determination of a single nutrient species. 15-17mL of sample is necessary for simultaneous determination of all analytes. It is entirely unnecessary to submit more than 20mL of sample. If you must submit more than 20mL of sample or have other volume concerns, please contact the Analytical Lab.
 
Mark all samples clearly and directly on the sample container, as well as the lid.  If you plan on shipping samples, any masking tape or colored lab-style tape placed on sample vials will fall off during shipment if in the presence of dry ice. Do not use these types of tape to label samples if you plan on shipping samples on dry ice.
 

Sample Preservation

Samples should be frozen immediately after collection and stored at -20°C or below.  Please allow sufficient headspace when freezing for expansion of the sample without breaking the container.
 
Do not acidify samples for nutrient analysis.
 
Frozen samples should be sent for analysis within one month of collection.  Shipping should be by overnight express, using insulated shipping containers and dry ice to keep the samples frozen during transport.

 

Rates

Nutrients Analysis

UC Rate

Non-UC Rate
Normal Seawater
(per sample, per analyte)
 $2.78 $4.21
Other (groundwater, surface water)
(per sample, per analyte)
 $3.62 $5.48

 

Analysts

Please feel free to contact us if you have any questions on Nutrient Analysis:
 
Bill Clinton, clinton@msi.ucsb.edu
Georges Paradis, paradis@msi.ucsb.edu