While doing our testing with nitrate kits a concern was raised about the cadmium waste that was being generated by all the teams.  Looking through the web I found The Nitrate Elimination Company, Inc. that was offering for testing their beta test kit that uses nitrate reductase(NaR) to catalyze reduction of nitrate to nitrite using NADH (a natural electron donor).  I e-mailed Ellen R. Campbell (vice president of the NECi) about our summer workshop and the idea of testing their kit against samples our teams were running using HACH, LaMotte, and GREEN test kits.  She wrote back quite promptly (4th of July weekend) and offered our workshop as many kits as would be needed for the testing.  I received two of the test kits and proceeded with getting samples from different teams (they gave me the sample and which test kit they used) and I ran their samples with the new kit.  Once I had run their samples I gave them my results and they gave me the readings they got from their kits.  What follows are the procedures for using the kit and results from Team 3's testing.  I thank all those who took time out of their projects to help me with this little study.

The kit came in a small cardboard box with 9 plastic bottles/vials containing:
                                a)  Assay buffer - liquid form - two 50 mL tubes
                                b)  NADH in solid form - two 5 mL tubes
                                c)  FD-NaR (nitrate reductase) - two 1 mL tubes (store at -20 celcius)
                                d)  Nitrate Standard (100 ppm nitrate-N) - one 1 mL tube
                                e)  Color Reagent 1 in solid form - one 60 mL amber bottle
                                f)   Color Reagent 2 in solid form - one 60 mL amber bottle

Additional equipment and supplies were needed to do the tests.  It is up to the person doing the testing to supply these items:
 
                                a)  Micro pipetters - .01 mL to .10 mL and .1 mL to 1.0 mL
                                b)  Means of mixing tubes
                                c)  Spectrophotometer or colorimeter (540 nm wavelength required)
                                d)  Glass or plastic cuvettes
                                e)  Test tubes as needed - they suggest 13X100 mm size
                                f)   Timer - stopwatch or clock okay)
                                g)  Deionized water - nitrate-free
                                h)  Sixty mLs of  3 N HCl

Several of the provided tubes needed to have water or HCl added to them to prepare them for use.  The NaR needed to be cooled on ice during testing.  The solutions were good for one day and were to be discarded at the end of the test day.  The kits contain materials to do two sets of 50 nitrate tests.  This kit is intended for the laboratory but could be adapted for field testing if need be.  All sample sizes and reagent amounts were delivered in the microliter range. Ranges were from 20 microliters to 1000 microliters.  I only had a 1 mL graduated pipette available (Thanks Ron from California) and the 20 microliter delivery was challenging.  I used a HACH portable spectrophotometer (Thanks Nancy from Alabama).  We did not have true cuvettes so we obtained small test tubes from the Biology institute.  In spite of these few differences in prodedural operations the use of the kit went very smoothly and the graph obtained from the nitrate standards I prepared came out quite reasonable - (See graph of nitrate standards).
The best-fit equation curve I got of the standard data was close to the nitrate standard curve given in the instructions manual.  Using my experimental curve and the curve in the instructions I calculated nitrate concentrations of the samples I received from my fellow institute members.  Below are the data and graph.

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