Hanna Instruments HI 83214 - Manual (Page 56)

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Phosphorus, Total
• Preheat the Hanna Reactor HI 839800 to 150 °C (302 °F). For correct use of the reactor follow Reactor
Instruction Manual.
Use of the optional HI 740217 safety shield is strongly recommended.
DO NOT USE AN OVEN OR MICROWAVE samples may leak and generate a corrosive and possibly
explosive atmosphere.
• Remove the cap from a Reagent Vial.
• Add exactly 5.0 mL of sample to the vial, while keeping the vial at a
45-degree angle.
• Add the content of one packet of Potassium Persulfate for Phosphorus
analysis. Replace the cap and shake gently the vial until all the powder is completely dissolved.
• Insert the vial into the reactor and heat it for 30 minutes at 150 °C.
• At the end of the digestion place the vials carefully in the test tube
rack and allow to cool to room temperature.
Warning: The vials are still hot, be careful when handling them.
• Select the Phosphorus, Total method following one of the
procedures described in the “Method Selection” section (see
page 15).
• Remove the cap from the vial and add exactly 2.0 mL of
Sodium Hydroxide (NaOH) Solution 1.54 N, while keeping the
vial at a 45-degree angle.
• Replace the cap tightly and mix by inverting the vial a couple
of times. This is the blank.
• Place the vial into the holder and push it completely down.