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a.r �• .Ar¢ � M a� AMMONIA (cont'd) APPENDIX. Lc Page Procedure 1. Measure 25 mL dcmineralized water in a clean 25-mL mixing graduated cylinder. 2. Take a water sample by filling a second clean 25-mL mixing graduated cylinder to the 25-mL mark. 3. Add the contents of one Salicylate Reagent Powder Pillow to each graduate,stopper tightly and mix vig- orously.See Note A. 4. After three minutes,add the contents of one Alkaline Qeanumre Powder Pillow,to each graduate;mix thoroughly. Allow at least 15 minutes for color to develop fully; sec Note B. The blank will be a yellow-green.The sample will be a dark-green when ammonia is present. 5. Pour the prepared demincralized water and the sample into separate,clean sample cells. 6. Place the sample cell containing the prepared demineralized water solution into the cell holder and close the light shield.Insert the appropriate Nitrogen Ammonia(Salicylate Methoti)Meter Scale into the meter. (Use meter scale 41766-00 for fresh water samples and meter stale 41769-00 for sea water samples.)Ad- just the Wavelength Dial to 655 nm. 7. Set the Mode Switch to LEFT SET and check the left set adjustment.If necessary,adjust the LEFT SET control to align the meter needle with the extreme left mark on the meter scale arc. B. Set the Mode Switch to NORM and adjust the RIGHT SET controls for a meter reading of zero mg/L-. 9. Place the prepared sample in the cell holder and close the light shield.Read the mg/L ammonia nitrogen (N). Notes A. All of the Salisylarc Reagent Powder must dissolve. �- B. ', c mixing graduates should be kept stoppered to prevent any ammonia fumes from affecting the test. C. The results may be expressed as mgr(,Ammonia(NH3)or mg/L Ammonium(NH4 )by multiplying the mg/L Ammonia Nitrogen(N)by 1.22 or by 1.29,respectively. D. The following ions interfere at concentrations exceeding those listed below: Calcium(Ca'2) I WO mg/L as CaCO3 Magnesium(Mg+2) 6000 mg/L as CaCO3 Nitrite(NO2-} 12 mg/L NO2 -N Sulfate,nitrate and phosphate do not interfere in concentrations normally found in surface water—At 3 least mp to 300 mg/i 50,-s.100 mg/L NO3-—N,and 100 mg1L PO,E_3—P. Sulfide will interfere by intensifying the color formed from ammonia and the reagents. Consult the Phenols procedure,Note B,for sulfide elimination. Iron interferes in the test but its effect may be eliminated by first determining the iron content of the sample (sec Iron,Total). If the demineralized water sample in Step 1 is made up with the same iron concentration as the sample end taken normally through the test,its use in Step 6 will blank out the effect of iron success- F, fully. is Less common interferences such as hydrazine and glycine will cause intensified colors in the prepared sample.It maybe raxwsary to distill the sample before the testis performed if numerous interferences are present.Using the Hach Distillation Apparatus,distill the test sample by following the procedure outlined in Note D of the Nessler Method Nitrogen,Ammonia lest. E. The sample may be adjusted to pH 7 with Sodium Hydroxide Standard Solution,IN, if the pH is less than 7 or Sulfuric Acid Standod Solution, 1N, if the pH is greater than 7. F.____Realdtaal chlorine must W-reinand fronithe sample:by the addition of SodiumArsrnitei Solutiom-Use 1--- --- -- -- ' mL of Sodium Arsenile Solution to remove 1 mg/L residual chlorine from a 250-m1.sample. More Sodium Amnite Solution should he used for higher chlorine concentrations, •L1,n Clwm.Ana ILIO)I I►e61 ''F - +` 'paRaan patieoma!-aefn 106M gots NnOff MnMd Aomori&NmaRnlael.