Environmental Express MicroBloc - Manual (Page 17)

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HotBlock: Operation and Instruction Manual MicroBlock TM Distillations
7.3 To a 50mL sample add 1N NaOH drop-wise with mixing and adjust to pH 9.5.
7.4 Transfer sample to the Reaction Tube, skirted, and add 2.5mL of borate buffer followed by a pinch of boiling chips.
7.5 To the Receiver Tube add 5-10mL of 20g/L Boric Acid or 0.2N H
2
SO
4
. If using the Snip & Pour concentrate pour the
entire contents of the tube in the Reaction Tube. The tip of the long stem must be below the level of boric acid or
sulfuric acid.
7.6 Repeat for all samples to be distilled up to a maximum of 10.
7.7 Assemble the distillation glassware setup as shown in Figure 3.
7.8 Turn on the tap water to cool the Cold Finger after ensuring all tubing connections are tight. Check for any leaks.
7.9 Turn the power ON and set heater block temperature to 190°C and the timer to 60 minutes.
7.10 Collect a minimum of 30mL of distillate.
7.11 Turn power OFF.
7.12 Unscrew the cap holding the Long Stem in the receiver tube and remove from all distillation positions to prevent
any suck back of the distilled sample. When the Long Stem is disconnected, gently let it rest at the bottom of the
Receiver Tube.
7.13 Dilute the distillate collected in the Receiver Tube to the 50mL graduation mark with ammonia-free water.
7.14 Place a collection tray or individual beakers located directly below where the Receiver Tubes were removed to catch
any further distillate. Distillation will continue because the heater block is still hot.
7.15 After each use clean exterior with a damp sponge.
7.16 When the heater temperature falls below 100°C, the next run can be started.
TOTAL Recoverable phenolics With the MicroBlock™
1.0 SCOPE AND APPLICATION
1.1 This method is for the
determination of phenolic
compounds in drinking,
ground, surface, and saline
waters, and domestic and
industrial wastes.
1.2 The applicable range is
2-500µg/L. The working
ranges are 2-200µg/L or 10-
500µg/L.
2.0 SUMMARY OF METHOD
2.1 This method is based on
the distillation of phenol
followed by the reaction
with alkaline ferricyanide
and4-aminoantipyrine. The
color complex is measured
at 505 or 520nm. Whether
the analysis is performed
by manual or automated
continuous flow analyzers, a
50mm path length measuring
optical cell is required to
achieve a detection limit of
2µg/L.
Figure 4 — Phenol glassware
Cold Finger
C5210
Cap C5213, and
PTFE-Faced Septa
C5218
Cap C5213, and
Silicone Sealing Ring
C5225
Short Stem
Outlet Tube
C5227
Receiver Tube
C5228
Distillation
Head
C5219
Reaction
Tube
C5214-B
Drain
Water Inlet