Page:NIOSH Manual of Analytical Methods - 5035.pdf/2

 SUPER ABSORBENT POLYMERS: METHOD 5035, Issue 1, dated 15 August 1994 - Page 2 of 6 EQUIPMENT:

REAGENTS: 1. Super absorbent polymer (the type present in air samples), 99+% pure if water is only impurity. See step 15 to determine the amount of water present. 2. Copper acetate, 0.07 M. Dissolve 27.96 g of cupric acetate monohydrate in water to make 2 L of solution. Solution may be stored at least 6 months. Filter solution through 0.45µm cellulose ester filter immediately (<4 h) before use. 3. Water, deionized. 4. Sucrose, 99+% pure. 5. Calibration stock mixture, ca. 4% super absorbent polymer by weight. Mix ca. 380 mg of polymer with 8000 mg of sucrose (do not use polymer which has been heated). Shake mixture 5 min by hand. Grind mixture to fine powder with freezer mill for 12 min (mill cooled with liquid nitrogen). 6. Nitric acid, 70%. 7. Perchloric acid, 70% (optional).* 8. Argon (for ICP-AES). 9. Acetylene (for AAS). 10. Air (for AAS). 11. Dilution acid, 2.8% HNO 3:0.7% HClO 4. Add 40 mL of 70% HNO 3 and 10 mL of 70% HClO 4 to deionized water to make 1 L of solution. 12. Dilution acid, 3.5% HNO 3. Add 50 mL of 70% HNO 3 to deionized water to make 1 L of solution.

1. Sampler: PVC filter, 37-mm membrane filter, 5-µm pore size, in two-piece filter cassette. 2. Personal sampling pump, 1 to 3 L/min, with flexible connecting tubing. 3. Instrument for measurement of copper (LOD <2 µg per sample); e.g., inductively coupled plasma-atomic emission spectrometer or atomic absorption spectrophotometer. 4. Vacuum filtration apparatus, two units (product XX10 025 00, Millipore Corp., Bedford, MA, or equivalent). 5. Filters, cellulose ester, 25-mm diameter, 0.45µm pore size. 6. Vials, 20-mL. 7. Pipets, 5- and 6-mL, with pipet bulb. 8. Balance, readable to five decimal places. 9. Ultrasonic bath. 10. Beakers, 50- and 250-mL. 11. Beakers, Phillips, 125-mL, with watch glass covers.** 12. Forceps. 13. Spatulas. 14. Freezer mill, or mortar and pestle. 15. Stirring rod, glass. 16. Hot plate, surface temperature, 150 °C.

Clean Phillips beakers with 70% nitric acid, and rinse thoroughly with deionized water before use.

See Special Precautions

SPECIAL PRECAUTIONS: Work with perchloric acid should be performed only in a perchloric acid hood.

SAMPLING: 1. 2.

3.

Calibrate each personal sampling pump with a representative sampler in line. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 1 and 3 L/min for a total sample size of 50 to 1500 L. Limit the loading of particulate matter on the filter to a maximum of about 1 mg. Seal the inlet and outlet of the sampler with plugs. Pack securely for shipment. Separately ship a bulk sample (20 g) of the super absorbent polymer.

SAMPLE PREPARATION: 4. 5.

Transfer the 37-mm PVC filter to a 20-mL vial, and allow the exposed side of the filter to face inward. Add 6 mL of 0.07 M copper acetate solution (filtered through a 0.45-µm cellulose ester filter NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94