Page:NIOSH Manual of Analytical Methods - 7903.pdf/2

 ACIDS, INORGANIC: METHOD 7903, Issue 2, dated 15 August 1994 - Page 2 of 6

EQUIPMENT:

1.	NaHCO3, reagent grade 2.	Na2CO3, reagent grade 3.	Distilled, deionized water, filtered through 0.45-μm membrane filter 4.	Eluent: bicarbonate/carbonate buffer solution (1.7 mM NaHCO3/1.8 mM Na2CO3). Dissolve 0.5712 g NaHCO3 and 0.7631 g Na2CO3 in 4 L filtered deionized water 5.	Calibration stock solutions, 1 mg/mL (as the anion). Dissolve salt in filtered deionized water a.	 Fluoride: 0.2210 g NaF/100 mL b.	 Chloride: 0.2103 g KCl/100 mL c.	 Phosphate: 0.1433 g KH2PO4/100 mL d.	 Bromide: 0.1288 g NaBr/100 mL e.	 Nitrate: 0.1371 g NaNO3/100 mL f.	 Sulfate: 0.1814 g K2SO4/100 mL

ST OR

IC


 * See SPECIAL PRECAUTIONS

1.	Sampler: glass tube, 11 cm x 7-mm OD, containing a 400-mg front section and 200mg backup section of washed silica gel, flamesealed ends with plastic caps. Front section is retained with a glass fiber filter plug. Urethane plugs separate and retain the backup section. Tubes are commercially available or may be prepared according to APPENDIX. 2.	Personal sampling pump, 0.2 to 0.5 L/min,with flexible connecting tubing 3.	Ion chromatograph, HPIC-AG4A anion separator and HPIC-AG4A anion micro membrane suppressor, conductivity detector, integrator and strip chart recorder. 4.	Waterbath: hotplate with beaker of boiling water 5.	Centrifuge tubes, 15-mL, graduated, plastic, with caps* 6.	Syringes, 10-mL, polyethylene with luer tip 7.	Filters, luer tip, with membrane filter, 13-mm, 0.8-μm pore size 8.	Micropipettes, disposable tips 9.	Volumetric flasks, 50- and 100-mL* 10.	Laboratory timer 11.	Bottles, polyethylene, 100-mL 12.	Auto sampler vials (optional)

AL

REAGENTS:

detergent, rinse thoroughly with deionized water, to minimize anion blank values.
 * Thoroughly clean glassware with mild

SPECIAL PRECAUTIONS:  Acids, particularly HF, are extremely corrosive to skin, eyes, and mucous membranes. HF will attack glass. Plastic labware is recommended. SAMPLING:

HI

1.	Calibrate each personal sampling pump with a representative sampler in line. 2.	Break ends of sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. 3.	Sample at an accurately known flow rate between 0.2 and 0.5 L/min for a total sample size of 3 to 100 L. NOTE: Do not exceed 0.3 L/min when sampling for HF. SAMPLE PREPARATION: 4.	Score sampler with a file in front of primary sorbent section. 5.	Break sampler at score line. Transfer glass fiber filter plug and front sorbent section to a 15-mL graduated centrifuge tube.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition