ASTM: D5316: 1,2-Dibromoethane and 1,2-Dibromo-3-Chloropropane in Water
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Official Method Name
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Standard Test Method for 1,2-Dibromoethane and 1,2-Dibromo-3-Chloropropane in Water by Microextraction and Gas Chromatography |
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Current Revision
| Current edition approved July 10, 1998. Originally published as D5316-92. |
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Media
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WATER |
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Instrumentation
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Gas Chromatography with Electron Capture Detection |
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Method Subcategory
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Organic |
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Method Source
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Citation
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Brief Method Summary
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This test method consists of microextraction of the sample followed by gas chromatographic analysis of the extract. An aliquot of the sample is extracted with hexane. Two mL of the extract are then injected into a gas chromatograph equipped with a linearized electron capture detector for separation and analysis. Aqueous calibration standards are extracted and analyzed in an identical manner as the samples in order to compensate for possible extraction losses. The extraction and analysis time is 30 to 50 min per sample, depending upon the analytical conditions chosen. Confirmatory evidence can be obtained using a dissimilar column. When component concentrations are sufficiently high, Gas Chromatography/Mass Spectrometric (GC/MS) methods may be used for confirmation analysis. |
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Scope and Application
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This test method covers the determination of 1,2-dibromoethane (commonly referred to as ethylene dibromide or EDB) and 1,2-dibromo-3-chloropropane (commonly referred to as DBCP) in water. |
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Applicable Concentration Range
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0.05-6.7 ug/L |
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Interferences
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Impurities contained in the extracting solvent usually account for the majority of the analytical problems. Solvent blanks should be analyzed on each new bottle of solvent before use. Indirect daily checks on the extracting solvent are obtained by monitoring the water blanks. Whenever an interference is noted in the water blank, the analyst should reanalyze the extracting solvent. Low-level interferences generally can be removed by distillation or column chromatography. This liquid-liquid extraction technique efficiently extracts a wide boiling range of nonpolar organic compounds and, in addition, extracts polar organic components of the sample with varying efficiencies. Current column technology suffers from the fact that EDB at low concentrations may be masked by very high levels of dibromochloromethane (DBCM), a common disinfection by-product of chlorinated drinking waters. |
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Quality Control Requirements
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Minimum quality control requirements are initial demonstration of proficiency, plus analysis of method blanks, quality control samples, and recovery spikes. In addition, duplicate samples may be required for specific programs. For a general discussion of quality control and good laboratory practices, see Practices D 4210 and D 5789 and Guide D 3856. |
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Sample Handling
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Collect the sample in accordance with Practice D 1066, Specification D 1192, and Practices D 3370, as applicable. Collect all samples in 40-mL bottles into which 3 mg of sodium thiosulfate crystals have been added to the empty bottles just prior to shipping to the sampling site. Alternately, add 75 mL of freshly-prepared sodium thiosulfate solution (0.04 mg/mL) added to empty 40-mL bottles just prior to sample collection. When sampling from a water tap, open the tap and allow the system to flush until the water temperature has stabilized (usually about 10 min). Adjust the flow to about 500 mL/min and collect samples from the flowing stream. When sampling from a well, fill a wide mouthed bottle or beaker with sample and carefully fill 40-mL sample bottles. Chill the samples to 4oC on the day of collection and maintain at that temperature until analysis. Field samples that will not be received at the laboratory on the day of collection must be packaged for shipment with sufficient ice to ensure that they will be <= 4oC on arrival at the laboratory. |
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Maximum Holding Time
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Store samples and field reagent blanks together at 4oC until analysis. The sample storage area must be free of organic solvent vapors. Analyze all samples within 28 days of collection. |
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Relative Cost
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Unknown |
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Sample Preparation Methods
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