Page:NIOSH Manual of Analytical Methods - 7102.pdf/2

BERYLLIUM and compounds, as Be: METHOD 7102, Issue 2, dated 15 August 1994 - Page 2 of 3 REAGENTS: 1. 2. 3. 4.

5.

6. 7.

EQUIPMENT:

Nitric acid, conc., reagent grade or better. Sulfuric acid, conc., reagent grade or better. Sodium sulfate, reagent grade. Sodium sulfate, 2% (w/v)/3% sulfuric acid (v/v). Add 10 g sodium sulfate and 15 mL H2SO 4 to deionized water. Dilute to 500 mL. Calibration stock solution, 1000 µg Be/mL,* commercially available, or dissolve 1.000 g Be metal in a minimum volume of 1:1 HCl, dilute to 1 L with 1% (v/v) HCl Argon, prepurified. Water, distilled or deionized.

See SPECIAL PRECAUTIONS.

1. Sampler: mixed cellulose ester membrane filter, 0.8-µm pore size, 37-mm diameter in two-piece cassette filter holder. 2. Personal sampling pump, 1 to 4 L/min, with flexible connecting tubing. 3. Atomic absorption spectrophotometer with graphite furnace and background corrector. 4. Beryllium hollow cathode lamp. 5. Pressure regulator, two-stage, for Argon. 6. Beakers, Phillips, 125-mL.* 7. Watchglasses.* 8. Volumetric flasks, 10-mL.* 9. Pipets, 10-mL volumetric, with pipet bulb.* 10. Automatic pipettor with tips, 10-µL and assorted sizes for standards. 11. Hotplate, 150 to 400 °C. 12. Waterbath, 60 to 70 °C. 13. Bottles, polyethylene, 25-mL.

Clean all glassware with conc. nitric acid and rinse thoroughly before use.

SPECIAL PRECAUTIONS: Beryllium is very toxic and a suspected human carcinogen [4]. Perform all acid digestions in a fume hood.

SAMPLING: 1. 2.

Calibrate each personal sampling pump with a representative filter in line. Sample at an accurately known flow rate between 1 and 4 L/min for a sample size of 25 to 1000 L. Do not exceed 2 mg total dust loading on the filter.

SAMPLE PREPARATION: 3. 4. 5.

6. 7. 8.

Open cassettes and transfer filters to clean Phillips beakers. Add 10 mL conc. HNO 3 and 1 mL conc. H 2SO 4. Cover with watchglass. Heat in fume hood on hotplate (150 °C) until brown fumes of HNO 3 disappear, then at 400 °C until dense fumes of H 2SO 4 appear. NOTE: Verify that the compounds in the samples are soluble with this ashing procedure, e.g., ore or mining samples will require HF in the digestion. If additional ashing acids are used (e.g., HF, HClO 4, or H 3PO 4), evaporate to complete dryness at this point. Cool and rinse watchglass and sides of beaker with distilled water and evaporate just to dryness. Remove beaker immediately and air-cool. Pipet 10.0 mL 2% Na 2SO 4/3% H 2SO 4 solution into beaker and cover. NOTE: Start sulfate reagent blanks at this step. Heat in 60 to 70 °C waterbath for 10 min. Allow to stand overnight before analysis to ensure complete dissolution of BeSO 4.

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