Environmental Express MicroBloc - Manual (Page 18)

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HotBlock: Operation and Instruction Manual MicroBlock TM Distillations
TOTAL Recoverable phenolics With the MicroBlock™ Continued
2.2 Phenol is used as the standard even though the various forms of phenol react differently with the colorimetric
reaction. The result obtained represents the minimum concentration present in the sample.
2.3 Reduced volume versions of this method that use the same reagents and molar ratios are acceptable provided they
meet the quality control and performance requirements stated in the method.
3.0 INTERFERENCES
3.1 Interferences from sulfur compounds are eliminated by acidifying the sample to a pH 4.0 and aerating briefly by
stirring.
3.2 Oxidizing agents such as chlorine detected by the liberation of iodine upon acidification in the presence of
potassium iodide are removed immediately after sampling by the addition of ferrous ammonium sulfate. If chlorine
is not removed, the phenolic may be partially oxidized and the results may be low.
3.3 Background contamination from plastic tubing and sample containers must be avoided. Use glass tubes
wheneverpossible.
3.4 Method interferences may be caused by contaminants in the reagent water, reagents, glassware , and other
processing apparatus that bias the analyte response.
4.0 CHEMICALS REQUIRED – DISTILLATION ONLY
4.1 Sodium Hydroxide
4.2 Sulfuric Acid
4.3 Ferrous Ammonium Sulfate – if chlorine is present at the time of sampling.
4.4 Phenol
4.5 Reagent Water ASTM Type II or Equivalent
4.6 Boiling Chips, Environmental Express # C5219
Note: The toxicities for each of the reagents used in this method are 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 EQUIPMENT AND SUPPLIES
5.1 The MicroBlock distillation glassware setup and tubing connections are shown in Figure 4 with short outlet tube.
Part Number Description
C5214-B Reaction Tube, Skirted
C5219 Distillation Head
C5210 Cold Finger
C5228 Receiver Tube
C5226 Short Stem Outlet Tube
6.0 REAGENT PREPARATION – DISTILLATION ONLY
6.1 Stock Phenol
Dissolve 0.50g phenol in 500mL reagent water. Add 0.25mL of concentrated sulfuric acid as a preservative.
1.0mL = 1.0mg phenol.
6.2 Standard Phenol, Solution A
Dilute 1.0mL of the Stock Phenol Solution to 100mL with reagent water.
1.0mL = 0.01mg phenol.