EPA-ORD / EPA-OST: 535 (ITMS): Chloroacetanilide and other acetamide herbicide degradates by solid phase extraction and liquid chromatography with tandem mass spectrometry with Ion Trap MS
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Official Method Name
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Measurement of chloroacetanilide and other acetamide herbicide degradates in drinking water by solid phase extraction and liquid chromatography/tandem mass spectrometry (LC/MS/MS)-Ion Trap MS |
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Current Revision
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Media
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WATER |
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Instrumentation
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Liquid Chromatography-Mass Spectrometery (also High Performance LC-MS; HPLC-MS) |
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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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Analytes and surrogate are extracted and concentrated by passing a 250-mL water sample through a solid phase extraction (SPE) cartridge containing 0.5 g of nonporous graphitized carbon. The compounds are eluted from the solid phase with a small quantity of methanol containing 10 mM ammonium acetate. The methanol extract is then concentrated to dryness and reconstituted with 1 mL of water containing 5 mM ammonium acetate. The analytes are chromatographically separated by injecting an aqueous aliquot (100 µL) into an LC system equipped with a reversed phase (C18) column. After elution from the column, the analytes are detected by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The concentration of each identified component is measured by an internal standard procedure, i.e. relating the product ion response of that compound to the product ion response of the compound that is used as an internal standard. A surrogate analyte, whose concentration is known in every sample, is measured with the same internal standard calibration procedure. Instrument: Ion Trap MS |
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Scope and Application
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This is a liquid chromatographic (LC)/tandem mass spectrometric (MS/MS) method applicable to the determination of the ethanesulfonic acid (ESA) and oxanilic acid (OA) degradates of the chloroacetanilide and other acetamide herbicides in finished drinking waters. The single laboratory Lowest Concentration Minimum Reporting Level (LCMRL) has also been determined in reagent water. The following compounds can be determined using this method: Acetochlor ESA, Acetochlor OA, Alachlor ESA, Alachlor OA, Dimethenamid ESA, Dimethenamid OA, Flufenacet ESA Flufenacet OA, Metolachlor ESA, Metolachlor OA, Propachlor ESA, and Propachlor OA. This method is intended for use by or under the supervision of analysts. |
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Applicable Concentration Range
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Interferences
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Interfering contamination may occur when a sample containing low concentrations of compounds is analyzed immediately after a sample containing relatively high concentrations of compounds. After analysis of a sample containing high concentrations of compounds, a laboratory reagent blank should be analyzed to ensure that accurate values are obtained for the next sample. Please refer to the method document for the entire discussion. |
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Quality Control Requirements
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Initial demonstration of laboratory capability, analysis of samples spiked with labeled compounds to evaluate and document data quality and the periodic analysis of laboratory reagent blanks, fortified blanks, and other laboratory solutions as a continuing check on performance. |
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Sample Handling
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All samples should be cooled (ice or chemical freeze packs) during shipment and must not exceed 10oC during the first 48 hours after collection. Samples must be confirmed to be at or below 10oC when they are received at the laboratory. Samples stored in the lab must be held at or below 6oC and protected from light until analysis. Samples should not be frozen. |
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Maximum Holding Time
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Extract within 14 days of collection. |
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Relative Cost
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Greater than $400 |
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Sample Preparation Methods
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Needs preservative prior to collection; 25-30 mg dry ammonium chloride for each 250-mL sample bottle |
