Marine Nitrate Testing

Question

What technology would be best for continuous or serial evaluation of marine nitrate levels?  
Most modern technologies appear developed for freshwater only.

Paul Curtis · Answer

Thank you for your answers.  I have been using colorimetric methods for years and was hoping to find a digital method that would be easier to record and monitor continuously.  i will look into the flow injection methods.

Lynn Egan · Answer

Nitrate can be measured in sea and brackish water using flow injection analysis. Samples over a salinity range of 0 to 35ppt can be analyzed. Copperized cadmium is used to reduce nitrate to nitrite. Nitrite is measured using sulfanilsmide and NED in acidic medium.
There are several vendors of this equipment. Lachat Instruments is one of them.

Ali Safarzadeh Amiri · Answer

Nitrate in seawater can be measured employing colorimetry and chemiluminescenece employing a variety of reagents. These methods have been reviewed/tabulated in the attached paper.

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