Nutrient Analyzer Overview


MLML houses a nutrient analyzer for low injection analysis, or FIA.  FIA is a continuous flow method for rapidly processing samples. The peristaltic pump draws a sample from the sampler into the injection valve. Simultaneously, reagents are continuously pumped through the system. The sample is loaded into the sample loop of one or more injection valves. The injection valve is then switched to connect the sample loop in line with the carrier stream. This sweeps the sample out of the sample loop and onto the manifold. The sample and reagents then merge in the manifold (reaction module) where the sample can be diluted, dialyzed, extracted, incubated and derivatized. Mixing occurs in the narrow bore tubing under laminar flow conditions. For each method, the operating parameters are optimized to address high sample throughput, high precision and high accuracy. 

Nutrients in freshwater and seawater are important to quantify in order to understand ecosystem health and anthropogenic impacts on water quality. Dissolved nutrients, including nitrate, nitrite, orthophosphate, ammonium, and silica, in water samples are analyzed colormetrically using our Lachat Quickchem 8000 Flow Injection Analyzer with an autosampler. The Lachat Autoanalyzer is a 5-channel system where all analytes can be measured in one sample aliquot simultaneously. 


$17 / sample for all analytes (seawater or freshwater)

$25 / sample (porewater)

$3 / sample for filtering (if samples arrive unfiltered)


  • A minimum of 15 mL of sample is required!
  • Samples will be frozen immediately upon arrival unless arrangements have been made to analyze unfrozen samples. Unfrozen samples must be analyzed within 48 hours and require prior approval.
  • A chain of custody form must be filled out completely for all batches of samples. The COC can be downloaded from this page or filled out at MLML during sample drop-off (please make appointment with Kim Null,
  • All small sample batches (<10 samples) will be charged an additional fee of $50

Quality Assurance/Quality Control analysis is also conducted on each run. We follow the State of California Surface Water Ambient Monitoring Program (SWAMP) Quality Assurance Program Plan to the best of our ability.

For more information contact:

Kim Null