Replacement Parts And Accessories - Hach Micro Dist Manuel D'utilisation

Problem
Results from the Micro
Dist methods do not
agree with other
methods
Temperature of the
block takes hours to
get to the temperature
set point
Collector tube cannot
be broken
Foam and/or debris on
the membrane
Distill a solid sample
Use different weights to identify the best weight of sample to add to each tube for each matrix type. If
the sample is high in organic content, use only 0.5 g or less of sample. If the sample is low in organic
content, use up to 1 g of sample.
Soil and sludge samples are diluted with deionized water. Calculate the amount of sample in mg/kg
after analysis:
A = C × ((1 L / l000 mL) × V)
B = A divided by (W × 1000 g/kg)
Where:
A = mg of analyte in the sample
B = mg of analyte per kg of sample (mg/kg)
C = determined concentration (mg/L)
V = dilution volume in tube (mL)
W = weight of the original sample (g)
If foam or debris continues to get on the collector tube membrane after the sample is decreased to
0.5 g:
1. Add 4–5 mL of deionized water instead of 6 mL to the sample tube.
2. Add activated charcoal to the sample tube so that it covers the surface of the solid.
3. Fill the empty space in the sample tube with glass wool.
Note: For soil or organic samples that contain cyanide, Biobeads
SM–2, are effective in laboratories.
Do a test on a known standard and a spiked sample that puts foam or debris on the membrane to
identify if these procedures correct the problem.

Replacement parts and accessories

Note: Product and Article numbers may vary for some selling regions. Contact the appropriate distributor or refer to
the company website for contact information.
Possible cause
Analytical method is not
calibrated with the Micro
Dist standards
Instrument failure
—
Soil or sludge sample is
high in organics (i.e.,
grease or oils)
Calibrate the analytical method with Micro Dist standards. If
the recoveries get better for reference samples, use Micro
Dist standards.
Note: Analytical methods used after the distillation must be scaled
down in proportion to the smaller Micro Dist sample.
When it takes more than 30–40 minutes for the instrument
to increase to the temperature setting, contact Technical
Support.
Use pruning shears or poultry scissors to cut the collector
tube at the break point.
Use a smaller sample size or less deionized water. Refer to
Distill a solid sample on page 23.
Note: Foam wets the hydrophobic membrane which causes the
membrane to let distilled sample back into the sample tube.
™
, manufactured by BIO-RAD, part number
Solution
English 23