Environmental Express SimpleDist C6000 Operation & Instruction Manual page 18

SimpleDist: Operation and Instruction Manual
Ammonia Nitrogen Distillation with the SimpleDist® Continued:
3.0 Interferences
3.1 Cyanate, which may be encountered in certain industrial effluents, will hydrolyze to some extent even at the pH of 9.5 at
which distillation is carried out.
3.2 Residual chlorine must be removed by pre-treatment of the sample with sodium thiosulfate or other reagents before
distillation.
4.0 Chemicals Required: Distillation Only
4.1 Ammonia-free water
4.2 Borate buffer solution
4.3 Sodium hydroxide, 1N
4.4 Boric acid catch solution (20g/L) – for use with the nesslerization and titration methods
4.5 Sulfuric acid catch solution, 0.04N – for use with the phenate and ion selective electrode methods
4.6 Sodium thiosulfate (for dechlorinating)
Note: The toxicity for each of the reagents used in this procedure is not fully documented. Treat each chemical as a potential health
hazard and limit exposure. Exercise good laboratory technique with an emphasis on safety.
5.0 Procedure
5.1 Adjust an aliquot of at least 25mL of sample to a pH of 9.5 using 1N sodium hydroxide and remove any residual
chlorine.
5.2 Pipette 25mL of pH-adjusted sample or an aliquot diluted to 25mL with reagent water into the SimpleDist® System
boiling tube. For solids weigh 1.0g +/- 0.01g and dilute to 25mL. Add boiling chips to the boiling tube.
5.3 Insert the inlet part liner into the green screw cap and thread assembly onto the top of the boiling tube.
5.4 Assemble inlet tube with funnel tip and insert into the smaller port on cap.
5.5 Pour the entire contents of the appropriate Snip & Pour trapping solution into the collection trap. The final
analytical method will determine which trapping solution you use. Generally, titration methods use boric acid
while other methods use sulfuric acid. If Snip & Pour tubes are not being utilized add a sufficient volume of the
appropriate trapping solution that will result in the proper final concentration after adding DI water to 25 mL.
(Example: 10 mL of 0.1 N H
solution to final volume. The trap may be attached to the glassware at this point or it may be filled off-line and then
placed onto the glassware. Attach tubing/adaptor to the collection trap.
5.6 Repeat steps 5.1 through 5.5 for all samples to be distilled.
5.7 Turn on the vacuum and adjust each valve to provide an air flow bubble rate of 10-15 bubbles per second for each
position as viewed in the collection trap. Vacuum should be sufficient to maintain slight negative pressure on the
assembly throughout the distillation.
Important: Monitor the vacuum to insure a back pressure does not build up in the boiling tube!
5.8 Add 1.25mL of borate buffer to the sample through the reagent inlet tube.
5.9 Turn the heat on and set the temperature of the HotBlock® to 135ºC. The block will achieve this temperature in
approximately 30 minutes. Heat for an additional 60 minutes after the block achieves this temperature.
5.10 Remove the collection trap from the assembly.
Important: Vacuum must remain on!
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SO solution) For best results wait until the distillation is complete to bring the trapping
2 4
System Operation
Environmental Express • 16