Page:NIOSH Manual of Analytical Methods - 5029.pdf/2

 4,4'-METHYLENEDIANILINE: METHOD 5029, Issue 2, dated 15 August 1994 - Page 2 of 5 EQUIPMENT:

REAGENTS: 1. 2. 3. 4. 5. 6. 7. 8.

9. 10.

4,4'-Methylenedianiline (MDA),* reagent grade. Acetonitrile, distilled in glass. Water, deionized. Sodium acetate, reagent grade. HPLC Mobile Phase: 0.1 N sodium acetate in 30% acetonitrile/70% water. Methanol, distilled in glass. Potassium hydroxide, reagent grade. Calibration stock solution,* 1.0 µg/µL. Dissolve 0.01 g MDA in 10 mL 0.1 N methanolic KOH. Extraction solution: 0.1 N potassium hydroxide in methanol. Sulfuric acid solution: 0.26 N in water. Add, with caution, 1.5 mL concentrated sulfuric acid to deionized water and dilute to 200 mL.



See SPECIAL PRECAUTIONS.

1. Sampler: filter, acid-treated glass fiber (Gelman AE or equivalent), with a paper O-ring, in a 37-mm polystyrene 3-piece cassette. NOTE: Prepare filter by adding 0.5 mL 0.26 N sulfuric acid to glass fiber filter on a glass tray. Heat for 1 hour at 100 °C. Load the filter, backed by a paper O-ring, into a cassette and seal with shrink band to enable open-face sampling. 2. Personal sampling pump, 1 to 2 L/min, with flexible tubing. 3. High performance liquid chromatograph (HPLC), with UV detector, 245-nm, and an electrochemical detector, glassy carbon electrode operated at +0.75 to +0.85V with reference to silver/silver chloride reference electrode, oxidative mode. 4. Wipe Tabs (Whatman Smear Tabs or equivalent). 5. Sample filter apparatus: 0.45-µm, PTFE. 6. Syringe, 10-mL, disposable. 7. Vials, glass, scintillation, 20-mL, with PTFE-lined caps. 8. Syringes, microliter, readable to 0.1-µL. 9. Pipets, 2-, 4-, and 10-mL. 10. Tweezers. 11. Ultrasonic water bath. 12. Gauze Pad (Johnson Gauze sponges 2x2, 12 ply or equivalent).

SPECIAL PRECAUTIONS: 4,4'-Methylenedianiline is a potential human carcinogen [4,5]. Avoid contact with acid and base solutions. Handle the acid-treated filters with care.

SAMPLING: 1. 2. 3. 4.

5.

Calibrate each personal sampling pump with a representative sampler in line. Remove the front piece and rear plug immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample open-faced at an accurately controlled flow rate between 1 and 2 L/min for a sample volume of 10 to 1000 L. Within 4 hours of completion of sampling, transfer the filter with tweezers to a glass vial. Discard the paper O-ring. Add 4.0 mL 0.1 N methanolic KOH. NOTE: Wipe sampling and skin pad instructions: a. Identify surfaces to be wiped, usually a 100-cm 2 area. b. Add wetting agent (isopropanol) if needed and wipe in square pattern. c. Place in 20-mL scintillation vial. d. If wetting agent was used, allow the solvent to evaporate. e. Add 0.1 N methanolic KOH to vial (10 mL for gauze pads, 2 mL for smear tabs). Pack securely for shipment. Include appropriate number of blanks in the shipment.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94