Hach DR2400 - Page 542

Organic Carbon, Total
Organic Carbon, Total
Page 4 of 6
OrganicCarbonTotal_Other_Low_DIR_Eng_Ody.fm
If the sample contains greater than 600 mg/L CaCO
3
alkalinity, lower the sample
pH to less than 7 before testing by adding Sulfuric Acid Solution
(Cat. No. 2449-32).
Most sample turbidity is either dissolved during the digestion stage or settled
during the cooling period. Sample turbidities up to 50 NTU have been tested
without interference.
Sampling and Storage
Collect samples in clean glass bottles. Rinse the sample bottle several times with
the sample to be collected. Fill the bottle completely full before capping. Test
samples as soon as possible. Acid preservation is not recommended.
Homogenize samples containing solids to assure representative samples.
Accuracy Check
Standard Additions Method (Sample Spike)
1. Prepare a 150-g/L C standard by transferring 15.00mL of 1000-mg/L C stock
solution to a 100-mL Class A volumetric flask. Dilute to volume with
organic-free water. Mix.
2. Use the TenSette
®
Pipet to add 0.1, 0.2, and 0.3 mL of the 150-mg/L C
standard to each of three Acid Digestion Vials.
3. Add the contents of one TOC Persulfate Powder Pillow to each vial.
4. Add 3.0 mL of sample to each vial. Swirl to mix.
Chloride 500 mg/L
Chlorine 10 mg/L Cl
2
Chlorine Dioxide 6 mg/L ClO
2
Copper 10 mg/L
Cyanide 10 mg/L CN
Iodide 50 mg/L
Iron (II) 10 mg/L
Iron (III) 10 mg/L
Magnesium 2000 mg/L as CaCO
3
Manganese (VII) 1 mg/L
Monochloramine 14 mg/L NH
2
Cl as Cl
2
Nitrite 500 mg/L NO
2
–
Ozone 2 mg/L O
3
Phosphate 3390 mg/L PO
4
3–
Silica 100 mg/L SiO
2
Sulfate 5000 mg/L SO
4
2–
Sulfide 20 mg/L S
2–
Sulfite 50 mg/L SO
3
2–
Zinc 5 mg/L
(continued)
Substance Maximum Level Tested