Page:NIOSH Manual of Analytical Methods - 5603.pdf/2

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ALACHLOR in AIR: METHOD 5603, Issue 1, dated 15 January 1998 - Page 2 of 5 EQUIPMENT:

REAGENTS:

1. Alachlor* Methanol*, pesticide analytical grade Deionized water Alachlor plate kit, EnviroGard™, or equivalent (e.g., Ohmicron RaPID Assay® or Ensys RIS®). 2. 5. Alachlor stock solution, 1000 µg/mL. Add 10 mg pure alachlorin 10 mL of pesticide free 3. methanol. Store in freezer. 4. 1. 2. 3. 4.

  • See SPECIAL PRECAUTIONS

5. 6. 7. 8. 9. 10.

11. 12. 13. 14. 15. 16.

Sampler: Solid phase extraction (SPE) disk, 25-mm, SDB-xc (3M Empore™, or equivalent), cellulose backup pad in 3-piece cassette with 50-mm extension. Personal sampling pump, 1 L/min, with flexible connecting tubing. Microtiter plate reader, 450 nm, 650 nm backup. Glass bottles, wide-mouth, ~1-oz. (diameter large enough to lay 25-mm disk flat), with PTFE-lined caps. Vials , glass, 4-mL, with PTFE-lined caps. Platform orbital shaker. Timer. Microtiter plate washer/shaker (optional). Pipettor, positive displacement. Pipettor, varichannel, multiwell with tips, 40and 80-µL (80- and 120-µL volume for larger sample numbers). Aerosol resistant tips (optional). Disposable reagent reservoir.. Forceps Protective gloves. Laboratory towels. Parafilm

SPECIAL PRECAUTIONS: NIOSH researchers have classified alachlor as a Group I compound, which is indicative of its adverseacute health effects from exposure to low concentrations. Handle carefully. Wear gloves and protective clothing. Methanol is flammable and moderately toxic by ingestion and inhalation.

SAMPLING: 1. 2. 3. 4.

Assemble each sampler in a clean environment. Calibrate each personal sampling pump with a representative sampler in line. Sample at an accurately known flow rate of ~1 L/min. The sampling period depends on suspected concentration. Seal both ends of the sampler with plugs and pack securely for shipment, including the appropriate number of blanks.

SAMPLE PREPARATION: 5.

Using forceps, remove the SDB disk from the sampler and place in a glass bottle with an ID large enough to allow the filter to lie flat. a. Add 2.0 mL of pesticide free methanol to the SDB disk, cap, and shake on a platform orbital shaker for 15 minutes. b. Transfer the methanol solution to a 4-mL sample vial with a PTFE-lined cap. c. Using a positive displacement pipettor or syringe, remove an aliquot of the sample and dilute it a minimum of 1:100 with deionized water. NOTE: If concentrations are higher than 0.5 µg/sample, further dilutions are needed to meet the target range of the assay. Multiple dilutions may be done if the concentration range is unknown. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition

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