7. At the time of measurements, prepare suitable working standards (e.g., 0–10 mg/l) for the calibration of the analyzer (see
Note 11). Pipette potassium hydrogen phthalate stock solution
and 2 mol/l HCl (200 μl/100 ml) into volumetric flasks, and
fill with ultrapure water (for blanks only ultrapure water and
HCl). Calibration standards should be made weekly.
8. Fill each calibration vial about 1/2 to 2/3 full, put on a plastic
film (see Note 12), and make holes on the film with a clean
syringe needle.
9. Prepare the carbon analyzer for analyses according to the operation manual (see Note 4).
10. Place standards in the autosampler of an analyzer, and run the
standards for a calibration curve and linearity test (see Note 5).
11. Take the samples out of refrigerator/freezer, and let them
come to room temperature.
12. Place the samples in an ultrasonic bath for 10 min.
13. Remove the lids, and put on a plastic film (see Note 12), and
make holes on the film with a clean syringe needle.
14. Run samples with the analyzer (see Note 13). Verify proper
operation of the instrument with reference material (Consensus Reference Water or equivalent), and include ultrapure
water blanks in the run (see Note 8).
3.3 Particulate
Organic Carbon
1. Prepare glass fiber filters by placing them in an acid bath (6%
HCl) for 4 h, and rinse then thoroughly with plenty of ultrapure water (see Note 14).
2. Combust the filters and aluminum circles for 4 h at 450
C, and
cool to room temperature.
3. Place a filter in the filtration device, and apply suction with the
vacuum pump.
4. Pipette a known volume of culture through the filter (see Note
15). Rinse with 5 ml ultrapure water to make sure all POC is on
the filter. For blanks use ultrapure water.
5. Remove the filter with forceps while the suction is on (see Note
16). Rinse the filtration device with ultrapure water between
samples.
6. Place the filter in the small Petri dish and dry it (see Note 17).
For blanks, place pure glass fiber filters in the Petri dishes.
7. Prepare a stock standard solution for POC by dissolving 1.340 g
glycine in ultrapure water, and add ultrapure water to a final
volume of 100 ml. Store the stock solution in a glass flask in a
refrigerator (stable for 1 month).
Determining Carbon Concentration
67
Note 11). Pipette potassium hydrogen phthalate stock solution
and 2 mol/l HCl (200 μl/100 ml) into volumetric flasks, and
fill with ultrapure water (for blanks only ultrapure water and
HCl). Calibration standards should be made weekly.
8. Fill each calibration vial about 1/2 to 2/3 full, put on a plastic
film (see Note 12), and make holes on the film with a clean
syringe needle.
9. Prepare the carbon analyzer for analyses according to the operation manual (see Note 4).
10. Place standards in the autosampler of an analyzer, and run the
standards for a calibration curve and linearity test (see Note 5).
11. Take the samples out of refrigerator/freezer, and let them
come to room temperature.
12. Place the samples in an ultrasonic bath for 10 min.
13. Remove the lids, and put on a plastic film (see Note 12), and
make holes on the film with a clean syringe needle.
14. Run samples with the analyzer (see Note 13). Verify proper
operation of the instrument with reference material (Consensus Reference Water or equivalent), and include ultrapure
water blanks in the run (see Note 8).
3.3 Particulate
Organic Carbon
1. Prepare glass fiber filters by placing them in an acid bath (6%
HCl) for 4 h, and rinse then thoroughly with plenty of ultrapure water (see Note 14).
2. Combust the filters and aluminum circles for 4 h at 450
C, and
cool to room temperature.
3. Place a filter in the filtration device, and apply suction with the
vacuum pump.
4. Pipette a known volume of culture through the filter (see Note
15). Rinse with 5 ml ultrapure water to make sure all POC is on
the filter. For blanks use ultrapure water.
5. Remove the filter with forceps while the suction is on (see Note
16). Rinse the filtration device with ultrapure water between
samples.
6. Place the filter in the small Petri dish and dry it (see Note 17).
For blanks, place pure glass fiber filters in the Petri dishes.
7. Prepare a stock standard solution for POC by dissolving 1.340 g
glycine in ultrapure water, and add ultrapure water to a final
volume of 100 ml. Store the stock solution in a glass flask in a
refrigerator (stable for 1 month).
Determining Carbon Concentration
67