Page:NIOSH Manual of Analytical Methods - 5508.pdf/2

 KEPONE: METHOD 5508, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3. 4. 5. 6. 7.

8.

EQUIPMENT:

Sodium hydroxide, 0.1 M, aqueous. Benzene, pesticide quality.* Methanol, pesticide quality.* Benzene:methanol, 99:1 (v/v).* Sulfuric acid, 0.05 M. Kepone.* Calibration stock solution, 50 µg/mL. Dissolve 100 mg Kepone in 99:1 benzene:methanol to make 10 mL solution. Dilute 50 µL of this solution to 10 mL with 99:1 benzene:methanol. Stable at least one week at 25 °C. Impinger recovery stock solution, 1 µg/mL. Dissolve 25 mg Kepone in methanol to make 10 mL solution. Dilute 4 µL of this solution to 10 mL with methanol.



See SPECIAL PRECAUTIONS.

1. Sampler: cellulose ester membrane filter, 0.8-µm, 37-mm, in a filter holder followed by a midget impinger with 15 mL 0.1 M NaOH. (Filter holder and impinger connected with short piece of plastic tubing.) 2. Sampling pump, 0.5 to 1 L/min, with flexible connecting tubing. 3. Impinger, midget, with stem removed. 4. Gas chromatograph, electron-capture detector, integrator and column (page 5508-1). 5. Forceps, two pairs. 6. Volumetric flasks, 10-mL. 7. Separatory funnel, 125-mL. 8. Syringes, 10-µL, readable to 0.1-µL; 100-µL, readable to 1 µL. 9. pH paper. 10. Pipet, 5-mL, with pipet bulb.

SPECIAL PRECAUTIONS: Methanol and benzene are flammable. Benzene and Kepone [3] are carcinogens. SAMPLING: 1. 2. 3. 4.

Connect the outlet of the impinger containing 15 mL 0.1 M NaOH and the inlet of the sampling pump to an empty impinger without a stem to protect the sampling pump from splash over. Calibrate the sampling pump with a representative sampler in line. Sample at an accurately known flow rate between 0.5 and 1 L/min for a total sample size of 50 to 600 L. Do not exceed 2 mg total dust loading on the filter. Separate the filter cassette and impinger for shipment to the laboratory.

SAMPLE PREPARATION: 5. 6. 7. 8.

9.

Use forceps to fold and transfer the filter to a 10-mL volumetric flask. Add 10.0 mL 99:1 benzene:methanol. Stopper and shake the flask vigorously for 1 min. Allow the flask to stand at least 2 h. Transfer the solution in the impinger to a separatory funnel. Wash the impinger with two 15-mL portions of 0.1 M NaOH, and add the washings to the separatory funnel. Add 0.05 M H2SO 4 until the pH is less than 7. Extract the Kepone with two 5-mL portions of benzene. Shake vigorously for 2 min and allow 5 min for the phases to separate. Combine the benzene layers in a 10-mL volumetric flask. Add 100 µL methanol and benzene to the mark.

CALIBRATION AND QUALITY CONTROL: 10.

Calibrate daily with at least six working standards in the range 1 to 50 ng/mL. a. Dilute 50 µg/mL calibration stock solution with 99:1 benzene:methanol to 3.6 µg/mL. b. Add known amounts of 3.6 µg/mL solution to 99:1 benzene:methanol in 10-mL volumetric flasks. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94