[Dogwap]

Hail all,

I'm making a 20% nitrogen solution from dry Ammonium Nitrate (34%N) and water for sale in the ag market.

Currently, we're using a hydrometer to determine the %N during conversion and then sending samples to the lab.

The lab uses AOAC 990.03 and the test only costs $10.

But we want to do the analysis onsite.

What equipment is needed?

Thanks,

[JGK]

The method you are citing is determination of nitrogen by total combustion.

The cost of new instrumentation to perform this will cost you in the order of US$50,000 - 60,000. The here's the cost of consummables.

Unless you will be doing thousands of samples annually it's just not worth purchasing.

[marquis]

One method commonly used in agricultural situations for determining nitrogen content is Near InfraRed (NIR) analysis.  Don't know if it would work in your application or not.

A older wet-chemical method is Kjeldahl.  It is relatively inexpensive.  But it takes a lot of time a some specialized equipment to run. 

[JGK]

One method commonly used in agricultural situations for determining nitrogen content is Near InfraRed (NIR) analysis.  Don't know if it would work in your application or not.

A older wet-chemical method is Kjeldahl.  It is relatively inexpensive.  But it takes a lot of time a some specialized equipment to run. 

The problem with NIR is the calibration. Rather than calibrating with reading v concentration, most NIR methods calibrate NIR reading vs classical analysis result. So initially, you would have to use the classical method to obtain your result anyway. Plus the cost of the NIR is once again in the order of $50,000.

[marquis]

Your point is well taken.

With the NIR we purchased, a requirement was put in the purchase order that the calibration and calibration testing be done by the company selling the NIR.  They had no problem with that clause.

Since cost is roughly equal, it boils down to operating cost and operating ease.  The buyer would need to evaluate those.

[JGK]

Ideally though NIR calibration should be an "organic system" as the calibration accuracy improves as more data points are entered.

There are also services such as this http://www2.qta.com/WhyQTA which you could consider

They place the NIR at your facility but data processing and the calibrations are  their responsibility.