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FIAlab Instruments, Inc.
14450 NE 29th Place STE 113
Bellevue, WA  98007 USA

Voice: 425-376-0450
Fax: 425-376-0451
fialab@flowinjection.com

              


              


Fluorometric Based Ammonia (Ultra Low for Fresh and Saline Waters)  

FIAlab standard method for the ultra low ammonia assay in fresh and seawater using the FIAlab-2500/2600/2700 system.  This method is also ideally suited to be run on the MicroSIA SIA system.

Assay Typical Throughput Concentration Range Notes
Ammonia (Ultra Low) 45 samples/hour 0.001 to 0.5 mg (N)/L NH3 Fluorometric detection

 


Principle:

Fluorometric ammonium orthophthaldialdehyde (OPA) analysis. Excitation around 370 nm, emmision 420- 500 nm.  

Comments:
 
This method requires the PMT-FL detection system for the lower levels, < 0.01.   With higher levels the USB2000FL can be utilized with the SMA-FL flowcell.   The water Bath Heater should be turned on to 75 C.  The flowrate of the pump should be set to 30. The FIA LOV connections B should be bridged by short green tubing.   

There are several variations of this method, with optimal settings depending on the type of samples and cocnentrations.   Please review the following references for further discussions.

References:

A Flow Injection-Fluorometric Method for the Determination of Ammonia in Fresh and Saline Waters with a View to In Situ Analysis. Alain Aminot, Roger Kerouel, Dominique Birot,  Ifremer-Brest,
BP 70, 29280 Plouzane´ , France First received 18 October 1999; accepted in revised form 29 August 2000.

Fluorometric determination of ammonia in sea and estuarine waters by direct segmented flow analysis Roger Khouel * , Alain Aminot IFREMER-Brest, BP 70, 29280 Plouzanf France Received 5 November 1996; revised 14 April 1997; accepted 16 April 1997.


Interferences:

Salinity concentrations of the sample comparing fresh and salt water can affect the response by ~10%.  This is overcome by having the standards in a similar matrix as the samples.

Reagents:

Carrier:
Milli-Q water spiked with 0.5% (v/v) ammonia free seawater or 0.2 g/l NaCl

 

Reagent 1: OPA Reagent 
*
Borate buffer solution: 30 g/l of disodium tetraborate decahydrate. The solution was slightly turbid and was filtered using a Whatman GF/C membrane. It remains stable for several months in a polyethylene vial.


*
OPA solution: 2 g of standard grade ophtaldialdehyde (P- 1378 Sigma Chemical) in 50 ml of ethanol (Carlo Erba 414607). Dissolution, performed in the dark by shaking, took a few minutes. This solution can be stored refrigerated in a glass bottle for at least 2 months.


*
Sulfite solution: 8 g/l of sodium sulfite. The solution was found to be stable for at least 2 months at room temperature in a glass bottle.


The working reagent Working reagent (WR). In a borosilicate bottle, 500 ml of borate buffer were introduced and the following reagents added, with mixing after each addition: 10 ml of OPA solution, 1 ml of sodium sulfite solution and 0.1 ml of a 30% Brij solution. This reagent, rapidly protected from light, was left to stand several hours.  It can be stored in the dark at room temperature for at least 2 months.

 

Reagent 2: Not used

Plug R2 port with Teflon Plug  

 


Standards:

100ml ICAMU-100  (ammonia standard)

Source: 727-524-7732 - www.exaxol.com 



Please email or phone FIAlab Instruments for additional product information.
Email:
fialab@flowinjection.com, Voice: 425-376-0450 or 1-800-963-1101,  Fax: 425-376-0451