Page:NIOSH Manual of Analytical Methods - 6001.pdf/2

 ARSINE: METHOD 6001, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3. 4. 5.

6.

7.

8. 9.

EQUIPMENT:

Water, distilled or deionized. Nitric acid, conc.* Nitric acid, 0.01 M. Dilute 0.4 mL conc. HNO 3 to 1 L with water. Nitric acid, 0.1 M. Dilute 4 mL conc. HNO 3 to 1 L with water. Arsenic stock solution, 1000 µg As(III)/mL.* Commercial standard or dissolve 1.322 g dried, certified reagent As 2O 3 in 100 mL 0.1 M HNO 3; dilute to 1 L with 0.1 M HNO 3. Calibration stock solution, 1.0 µg As(III)/mL.* Dilute 0.1 mL arsenic stock solution (1000 µg As/mL) to 100 mL with 0.01 M HNO 3. Prepare fresh daily. Nickel nitrate solution, 1000 µg Ni/mL. Commercial nickel atomic absorption standard or dissolve 3.112 g dried reagent Ni(NO 3)2 in 100 mL 0.1 M HNO 3; dilute to 1 L with water. Argon, compressed. Arsine, *99%, or certified mixture in nitrogen.



See Special Precautions

1.

2. 3.

4. 5. 6. 7. 8. 9.

Sampler: glass tube, 7 cm long, 6-mm OD, 4-mm ID, flame-sealed ends, containing two sections of activated (600 °C) coconut shell charcoal (front = 100 mg; back = 50 mg) separated by a 2-mm urethane foam plug. A silylated glass wool plug precedes the front section and a 3-mm urethane foam plug follows the back section. Pressure drop across the tube at 1 L/min airflow must be less than 3.4 kPa. Tubes are commercially available. NOTE: Use a cellulose ester membrane filter in front of the sampler if particulate arsenic is present [3,4]. Personal sampling pump, 0.01 to 0.2 L/min, with flexible connecting tubing. Atomic absorption spectrophotometer with graphite furnace, non-pyrolytic tubes, background correction and electrodeless discharge (and power supply) or hollow cathode lamp for arsenic. Volumetric flasks, 1-L and 100-mL.* Micropipets, 5- to 500-µL.* Centrifuge tubes, 10- or 15-mL.* Ultrasonic bath. Centrifuge. Syringe, gas, 0.1-mL, readable to 1 µL. rinse thoroughly with distilled or deionized water before use.
 * Clean all glassware with conc. nitric acid and

SPECIAL PRECAUTIONS: Arsenic is a human carcinogen [7]. Perform all concentrated acid handling in a fume hood. Arsine is extremely poisonous by inhalation. Handle in well-ventilated hood.

SAMPLING: 1. 2.

3. 4.

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. NOTE: Use a cellulose ester membrane prefilter if particulate arsenic compounds may be present [3,4]. Sample at an accurately known flow rate between 0.01 and 0.2 L/min for a total sample size of 0.1 to 10 L. Cap the sampler with plastic (not rubber) caps and pack securely for shipment.

SAMPLE PREPARATION: 5. 6.

Place the front and back sorbent sections of the sampler tube in separate centrifuge tubes. Discard the glass wool and foam plugs. Add 1.0 mL 0.01 M HNO 3 to each tube. Cap each tube. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94