Page:NIOSH Manual of Analytical Methods - 6011.pdf/3

 CHLORINE AND BROMINE: METHOD 6011, Issue 2, dated 15 August 1994 - Page 2 of 5 EQUIPMENT:

REAGENTS: 1. 2. 3. 4.

5.

6.

Sodium thiosulfate, reagent grade. Water, deionized. Extraction solution: 6 m M Na 2S2O 3. Dissolve 0.474 g Na 2S2O 3 in 500 mL deionized water. Eluent: 0.25 m M NaHCO 3/4 mM Na 2CO 3/0.78 m M p-cyanophenol. Dissolve 0.041 g NaHCO 3, 0.848 g Na 2CO 3 and 0.186 g p-cyanophenol in 2 L filtered deionized water. Suppressor regenerant, 0.025 N H2SO 4. Dilute 2.8 mL conc. H 2SO 4 to 4 L with deionized water.* Calibration stock solutions, 1 mg/mL (as anion). (1) Dissolve 0.149 g KBr in 100 mL deionized water (2) Dissolve 0.21 g KCl in 100 mL deionized water.



See SPECIAL PRECAUTIONS.

1. Sampler: Silver membrane filter,* 25-mm, 0.45-µm, (Costar/Nuclepore, Poretics, or equivalent) with porous plastic support pad (Costar/Nuclepore); prefilter, PTFE with PTFE support, 0.5-µm (Gelman Zefluor, SKC, or equivalent), or polyester, 0.4-µm (Costar/Nuclepore) with porous plastic support pad; three-piece, 25-mm carbon-filled polypropylene cassette (opaque) with 50-mm extension (Costar/Nuclepore or Gelman) (Fig. 1). a. In the outlet piece of cassette, place porous plastic support pad and cleaned silver filter. Insert 50-mm extension (cowl) securely. b. At the inlet (top) of the extension, place porous plastic support pad and prefilter. Insert inlet cassette piece securely. c. Seal each connection with shrinkable bands or tape. 2. Personal sampling pump, 0.3 to 1 L/min, with flexible connecting tubing. 3. Ion chromatograph with Dionex MFC-1, HPICAG4A, HPIC-AS4A columns, AMMS anion micromembrane suppressor, conductivity detector and integrator (page 6011-1). 4. Bottles, 30-mL, wide mouth with screw caps, amber or opaque polyethylene. 5. Micropipettes, with disposable tips. 6. Volumetric flasks, 10- and 100-mL. 7. Repipet reagent dispensers, 0 to 10-mL. 8. Syringes, 10-mL, polyethylene, luer-tip. 9. Forceps.

Silver membrane filters must be cleaned prior to use (see APPENDIX A). NOTE: Some lots of silver membrane filters contain excessively high chloride background levels. Please screen before field use.

SPECIAL PRECAUTIONS: Sulfuric acid is extremely corrosive to skin, eyes, and mucous membranes. Wear protective clothing. Handle in a fume hood.

SAMPLING: 1. 2. 3. 4.

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 0.3 and 1 L/min for a total sample size of 8 to 360 L for bromine or 2 to 90 L for chlorine. Seal ends of sampler with plugs. Pack securely for shipping.

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