Environmental Express MicroBloc - Manual (Page 16)

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HotBlock: Operation and Instruction Manual MicroBlock TM Distillations
Ammonia Distillation with the MICROBLOCK TM Continued
4.7 Reagent Water ASTM Type II or Equivalent, especially ammonia-free
Note: Such water is best prepared by passage through an ion-exchange column containing a strongly acidic cation exchange
resin mixed with a strongly basic anion exchange resin.
4.8 Boiling Chips, Environmental Express # C5219
5.0 EQUIPMENT AND SUPPLIES
5.1 The MicroBlock distillation glassware setup and tubing connections are shown in Figure 3 with long outlet tube.
Part Number Description
C5214-B Reaction Tube, Skirted
C5219 Distillation Head
C5210 Cold Finger
C5228 Receiver Tube
C5226 Long Stem
C7010 Snip & Pour, 0.2N H
2
SO
4
, 50 x 10mL
C7120 Snip & Pour, 20g/L Boric Acid, 50 x 10mL
6.0 REAGENT PREPARATION – DISTILLATION ONLY
6.1 Sodium Hydroxide, 0.1N
Dissolve 4g of NaOH in reagent water and dilute to 1L.
6.2 Sodium Tetraborate Solution, 0.025 M
Dissolve 5.0g of Na2B4O7 [anhydrous] or 9.5g of Na2B4O7 :10H2O and dilute to 1L with reagent water.
6.3 Borate Buffer Solution
Add 88mL of 0.1N Sodium Hydroxide solution to 500mL of 0.025 M sodium tetraborate and dilute to 1L with reagent
water.
6.4 Sodium Thiosulfate Solution
Dissolve 3.5g Na2S2O3 : 5H2O to 1L of reagent.
Note: One mL of this solution will remove 1mg/L of residual chloride in 500mL of sample.
6.5 Sodium Sulfite Solution
Dissolve 0.9g Na2SO3 :5H2O to 1L of reagent water.
Note: One mL of this solution will remove 1mg/L of residual chlorine in 500mL of sample.
6.6 Stock Ammonium Chloride
Dissolve 3.819g of anhydrous ammonium chloride, previously dried at 105°C, and dilute to 1L with reagent water.
1.0mL = 1.0mg NH3-N.
6.7 Standard Ammonium Chloride, Solution A
Dilute 10.0mL of Stock Solution to 1L with reagent water.
1.0mL = 0.01mg NH3-N.
6.8 Standard Ammonium Chloride, Solution B
Dilute 10.0mL of Stock Solution A to 100mL with reagent water.
1.0mL = 0.001mg NH3-N.
7.0 PROCEDURE
7.1 Preparation of distillation glassware. Steam out the distillation glassware using 50mL reagent water with a
pinch of boiling chips until no trace of ammonia can be detected.
7.2 If residual chlorine is present add sodium thiosulfate or sodium sulfite equivalent to the chlorine level.