Chlorine
-Residual Chlorine (By SM 4500-Cl B-2011)
Scope:
The iodometric method is suitable for measuring total chlorine concentrations greater than 1 mg/L in natural and treated waters. Not applicable to estuarine or marine waters.
Chlorine will liberate free iodine from potassium iodide (KI) solutions at pH 8 or less. The liberated iodine is titrated with a standard solution of sodium thiosulfate (Na2S2O3) with starch as the indicator. Titrate at pH 3 to 4 because the reaction is not stoichiometric at neutral pH due to partial oxidation of thiosulfate to sulfate.
-Standard Methods Online – Standard Methods for the Examination of Water and Wastewater
Method Data
| Method 4500-Cl B | |
|---|---|
| Hold Time | 0.25 hour |
| Preservation | Chlorine in aqueous solution is not stable, and the chlorine content of samples or solutions, particularly weak solutions, will decrease rapidly. Exposure to sunlight or other strong light or agitation will accelerate the reduction of chlorine. Therefore, start chlorine determinations immediately after sampling, avoiding excessive light and agitation. |
| Sample Volume | 250 mL |
| Collection Method | grab |
| Instrumentation | spectrometer |
| Method Refernce | SM 4500-Cl B |
Analyte List
| Analyte | Formula | CAS Number |
|---|---|---|
| Chlorine | Cl |
*Please contact our project management team for more information about reporting limits and other specific project needs.
Chlorine
–Inorganic Anions by Ion Chromatography (By EPA 300.0)
Scope:
Part A of the test method covers the determination of common inorganic anions in drinking water, surface water, mixed domestic and industrial wastewaters, groundwater, reagent waters, solids (after extraction), leachates (when no acetic acid is used). Part B of the test method covers the determination of bromate, chlorate, and chlorite in drinking and reagent waters.
A small volume of sample, typically 50-100 uL, is introduced into an ion chromatograph. The anions of interest are separated and measured, using a system comprised of a guard column, separator column, suppressor device, and conductivity detector.
-Methods for the Determination of Inorganic Substances in Environmental Samples (EPA/600/R-93/100)
Method Data
| Method 300.0 | |
|---|---|
| Hold Time | Part A: 48 Hours (NO2-N, NO3-N, orthophosphate-P) 28 days (others) Part B: Bromate and Chlorate (28 days) and chlorite (14 days with preservation -- otherwise analyze immediately). |
| Preservation | Part A: No preservation is required for bromide, chloride, or fluoride. Refrigerate samples at 4 degrees C for nitrate-N, nitrite-N, orthophosphate-P, and sulfate. Samples being tested for nitrate/nitrite should be adjusted to pH < 2 with concentrated H2SO4 and refrigerated at 4 degrees C until analysis. Analyze samples being tested for bromide, chloride, fluoride, nitrate/nitrite, and sulfate within 28 days. Analyze samples being tested for nitrate-N, nitrite-N, and orthophosphate-P within 48 hours. Part B: Samples analyzed for bromate and chlorate may be held for 28 days without preservation. Chlorite should be analyzed for immediately (within 10 minutes). However, if the sample cannot be analyzed immediately, it may be preserved for up to 14 days if treated with ethylenediamine (ClO2 should be removed prior to this step) and chilled to 4oC. |
| Sample Volume | 250mL HDPE bottle |
| Instrumentation | Ion Chromotography |
| Method Refernce | 300 |
Analyte List
| Analyte | Formula | CAS Number |
|---|---|---|
| Chlorine | Cl |
*Please contact our project management team for more information about reporting limits and other specific project needs.
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