3 Methods
Use acid-washed glassware (soaked for 4 h in 6% HCl and rinsed
with deionized water).
3.1 Dissolved
Inorganic Carbon
1. Combust the sample bottles and aluminum cups for 4 h at
450
C, and cool them to room temperature before use.
2. Prepare standards by weighing sodium bicarbonate (0–100 mg)
in small aluminum cups (see Note 1). Put the cup into a 100 ml
volumetric flask, and fill up with ultrapure water.
3. Prepare acid solution for DIC analyzer (see Note 2).
4. Take samples and put it in BOD bottle. The samples can be
stored in a refrigerator for a short time (1–2 h) (see Note 3).
5. Prepare the carbon analyzer for analyses according to the operation manual (see Note 4).
6. Place standards in the autosampler of an analyzer for a calibration curve and linearity test (see Note 5), or measure the standards manually (see Note 6).
7. The samples might need to be prepared before analyses by
filtering (see Note 7).
8. Run the samples with the analyzer or manually by measuring
3–5 replicates per sample. Verify proper operation of the instrument with reference material, and include ultrapure water blanks
in the run (see Note 8).
9. In manual analyses, calculate DIC concentration by the calibration curve (see Note 9).
3.2 Dissolved
Organic Carbon
1. Combust glass vials and filters for 4 h at 450
C, and cool them
to room temperature before use.
2. Prepare 2 mol/l HCl by dissolving 33.2 ml concentrated
hydrochloric acid in ultrapure water, and fill up to a volume
of 200 ml. Store in a glass bottle.
3. Filter the sample with the syringe and syringe filter. Rinse the
syringe with the sample before filtering. Discard first 5 ml of the
filtrate and collect 20 ml into the glass vial. Prepare filter blank
by filtering ultrapure water.
4. Add 80 μl, 2 mol/l HCl to the glass vial.
5. Put on the lid, and place the glass vial in a refrigerator or freezer
until it can be run in the carbon analyzer (see Note 10).
6. Prepare a stock standard solution containing 1000 mg C/l by
dissolving 2.125 g potassium hydrogen phthalate (pre-dried at
105
C for 1 h) in ultrapure water, and then add ultrapure
water to a final volume of 1 l. Store the stock solution in a glass
flask in the refrigerator (stable for 1 month).
66
Jaana Koistinen et al.
Use acid-washed glassware (soaked for 4 h in 6% HCl and rinsed
with deionized water).
3.1 Dissolved
Inorganic Carbon
1. Combust the sample bottles and aluminum cups for 4 h at
450
C, and cool them to room temperature before use.
2. Prepare standards by weighing sodium bicarbonate (0–100 mg)
in small aluminum cups (see Note 1). Put the cup into a 100 ml
volumetric flask, and fill up with ultrapure water.
3. Prepare acid solution for DIC analyzer (see Note 2).
4. Take samples and put it in BOD bottle. The samples can be
stored in a refrigerator for a short time (1–2 h) (see Note 3).
5. Prepare the carbon analyzer for analyses according to the operation manual (see Note 4).
6. Place standards in the autosampler of an analyzer for a calibration curve and linearity test (see Note 5), or measure the standards manually (see Note 6).
7. The samples might need to be prepared before analyses by
filtering (see Note 7).
8. Run the samples with the analyzer or manually by measuring
3–5 replicates per sample. Verify proper operation of the instrument with reference material, and include ultrapure water blanks
in the run (see Note 8).
9. In manual analyses, calculate DIC concentration by the calibration curve (see Note 9).
3.2 Dissolved
Organic Carbon
1. Combust glass vials and filters for 4 h at 450
C, and cool them
to room temperature before use.
2. Prepare 2 mol/l HCl by dissolving 33.2 ml concentrated
hydrochloric acid in ultrapure water, and fill up to a volume
of 200 ml. Store in a glass bottle.
3. Filter the sample with the syringe and syringe filter. Rinse the
syringe with the sample before filtering. Discard first 5 ml of the
filtrate and collect 20 ml into the glass vial. Prepare filter blank
by filtering ultrapure water.
4. Add 80 μl, 2 mol/l HCl to the glass vial.
5. Put on the lid, and place the glass vial in a refrigerator or freezer
until it can be run in the carbon analyzer (see Note 10).
6. Prepare a stock standard solution containing 1000 mg C/l by
dissolving 2.125 g potassium hydrogen phthalate (pre-dried at
105
C for 1 h) in ultrapure water, and then add ultrapure
water to a final volume of 1 l. Store the stock solution in a glass
flask in the refrigerator (stable for 1 month).
66
Jaana Koistinen et al.