AMINOETHANOL COMPOUNDS I: METHOD 2007, Issue 2, dated 15 August 1994 - Page 2 of 5 EQUIPMENT:
REAGENTS: 1. Eluent: Four parts methanol to one part distilled water (v/v). NOTE: Do not use deionized water which may contain formaldehyde. 2. Analyte, reagent grade.* 3. Alkalinizing solution: 0.20 N NaOH (8.0 g NaOH/L) in eluent. 4. HCl, conc. (38%, 12 N) (needed for field use).* 5. HCl, 0.12 N, in eluent. Dilute 10.0 mL conc. HCl with eluent to make 1 L solution. 6. Benzaldehyde. 7. Calibration stock solutions, 10 mg/mL, in 0.12 N HCl in eluent for each analyte. 8. Nitrogen or helium, purified. 9. Hydrogen, prepurified. 10. Air, filtered. 11. pH paper. 12. KOH, saturated solution. 13. Glass wool.
See SPECIAL PRECAUTIONS.
SPECIAL PRECAUTIONS: The analytes are eye irritants [5]. Avoid skin contact or inhalation of conc. HCl.
SAMPLING: 1. 2. 3.
4.
5.
1. Sampler: glass tube, 7-cm long, 8-mm OD, 6-mm ID, flame-sealed ends with plastic caps, containing two sections of 45/60 mesh chromatographic grade silica gel (front = 300 mg; back = 150 mg) separated by a plug of silylated glass wool. A silylated plug of glass wool is at each end of the tube. Pressure drop across the tube at 0.2 L/min airflow must be less than 3.2 kPa. Tubes are commercially available. Do not use sampling tubes constructed with metal parts or urethane foam plugs. Conc. HCl will react with these materials. 2. Personal sampling pump, 0.01 to 0.2 L/min, with flexible connecting tubing. 3. Syringe for dispensing HCl, 50-µL with glass barrel, PTFE-tipped plunger and inert (platinum or PTFE) needle (for field use). 4. Gas chromatograph, FID, integrator and column (page 2007-1). 5. Coated capillary injection port liner: Soak liner and small quantity of glass wool in saturated KOH. Air-dry liner and glass wool. Loosely pack glass wool in liner. 6. Vials, 2-mL, glass, PTFE-lined crimp caps. 7. Volumetric flasks, 10-mL. 8. Syringe, 10-µL, readable to 0.1 µL. 9. Micropipets, 10- to 100-µL. 10. Pipets, 0.5- and 2-mL, with pipet bulb.
Calibrate each personal sampling pump with a representative sampler in line. Break the ends of the sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.01 and 0.2 L/min for a total sample size of 4 to 24 L. NOTE: If samples are to be eluted immediately or will be stored in a freezer for less than 14 days, the following step may be eliminated. Immediately after sampling, stabilize the samples by adding exactly 20 µL conc. HCl to each section of silica gel in each sampler using a syringe. NOTE 1: The amount of HCl added must be measured carefully because the sample will be neutralized and made alkaline (step 9) for proper chromatography. NOTE 2: Iron impurities in silica gel will turn yellow upon addition of acid. Cap the samplers. Pack securely for shipment.
SAMPLE PREPARATION:
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
