NEMI Method Summary

Method Summary Information

Method Number: D4658 Media: WATER
Revision: 1992
Method Source: ASTM International
Subcategory: INORGANIC Analytes in this method
Official Name: Standard Test Method for Sulfide Ion in Water
Descriptive Name Sulfide in Water
Source Info: ASTM International
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Citation: ASTM Volume 11.02
 
Brief Method
Summary:
 Sulfide ion is measured potentiometrically using a sulfide ion-selective electrode in conjunction with a double-junction sleeve type reference electrode. Potentials are read using a pH meter having an expanded millivolt scale capable of being read to the nearest 0.1 mV, or a specific ion meter having a direct concentration scale for sulfide ion.
Scope And
Application:
 This test method uses an ion-selective electrode to determine sulfide ion in water. The test method is applicable in the range from 0.04 to 4000 mg/L of sulfide. Precision data presented in this test method were obtained using reagent water only. It is the user's responsibility to ensure the validity of this test method for untested types of water.
Applicable
Conc Range:
 0.04 - 4000 mg/L
Interferences: Samples are treated prior to analysis with sulfide antioxidant buffer (SAOB). This buffer fixes the solution pH at a highly alkaline level and contains ascorbic acid to retard air oxidation of sulfide ion in solution. This ensures that the sulfide present occurs chiefly as S = ion rather than as complexed HS- or H2S that are present at lower pH values.
QC Requirements:
Sample Handling: Collect samples in accordance with Practices D 3370. Samples should be taken with a minimum of aeration to avoid air oxidation of sulfide or loss of volatile hydrogen sulfide from the sample. Preserve samples by adding 0.2 mL (4 drops) of 2 M zinc acetate (equivalent to 128 mg/L S2- ) and 0.05 mL (1 drop) of 6 M sodium hydroxide to a 100-mL bottle. Fill the bottle completely with the sample and stopper it. There should be no air bubbles trapped under the stopper. If the concentration of sulfide is greater than approximately 100 mg/L, the amounts of both reagents should be increased. Sulfide in samples that have been "preserved" with zinc acetate can be determined without special treatment, since SAOB contains EDTA to redissolve the zinc and free the sulfide. The entire sample is used for analysis, and since the results will be given in milligrams sulfide per litre, the sample volume must be known.
Max Holding Time:
 
Relative Cost: Unknown
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