Page:NIOSH Manual of Analytical Methods - 3516.pdf/2

 CROTONALDEHYDE: METHOD 3516, Issue 1, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3. 4. 5.

6.

7. 8.

9.

EQUIPMENT:

Hydroxylamine hydrochloride, reagent grade. Sodium hydroxide, 0.1 M, reagent grade. Formic acid, reagent grade. Sodium formate, reagent grade. Hydroxylamine collection solution. Dissolve 0.68 g of hydroxylamine hydrochloride in 1 L deionized water. Adjust to pH 5 with 0.1 M sodium hydroxide. Formic acid/sodium formate buffer. Add 3.4 g sodium formate and 2 mL formic acid to 500-mL volumetric flask. Bring to volume with deionized water. Crotonaldehyde,* 85%. Crotonaldehyde stock solution. Prepare solutions containing 17.19 and 1.179 mg/mL of crotonaldehyde in deionized water. Nitrogen, prepurified.



See SPECIAL PRECAUTIONS.

1. 2.

3.

4. 5. 6. 7. 8.

Glass midget bubblers. Personal sampling pump, 0.1 to 0.2 L/min, and trap with flexible tubing. Trap is a midget bubbler or impinger with stem broke off. Volumetric flasks, 1-L, 500-mL, and convenient sizes for preparing stock standard solutions. Pipets, 10-mL, 5-mL, and other convenient sizes. Syringes for preparing spiked standard samples. Potentiostat with differential pulse polarographic capability. China marker. PTFE tubing 15 cm x 7-mm ID or PTFE plugs for sealing the inlet and outlet of the bubbler stem before shipment.

NOTE: Wash all glassware with detergent, rinse with deionized water and dry. Midget bubblers should be heated in an oxidizing atmosphere at about 580 °C to remove organic contaminants.

SPECIAL PRECAUTIONS: Crotonaldehyde is highly toxic, flammable liquid [5]. Prevent contact SAMPLING: with skin, eyes, and clothing. Do not breathe vapors; crotonaldehyde vapors irritate the mucous 1. Calibrate each personal sampling pump membranes, nose and respiratory tract. Vapors with a representative sampler and trap in can severely irritate the eyes, causing lacrimation. line. Contact with eyes can cause corneal burns. 2. Rinse bubblers with 10 mL hydroxylamine Contact with skin causes irritation and may cause solution. Pipet 10 mL of hydroxylamine burns. Wash thoroughly after handling. solution buffered at pH 5 into each midget bubbler. Mark the liquid level on the bubbler with a china marker. Ensure that bubbler frit is covered. 3. Attach outlet of midget bubbler to inlet of trap used to protect pump during sampling. Attach trap to pump with metal holder. Connect outlet of trap to pump by flexible tubing. 4. Sample at an accurately known flow rate between 0.1 and 0.2 L/min for a total sample size of 1 to 49 L. NOTE: Sampled air should not pass through any tubing containing polyvinylchloride (PVC) before entering the bubbler; PVC tubing is known to give interferences in the method. 5. Discard any material collected by the trap. If more than 1 mL of material is collected in the trap, the sample should be considered invalid. 6. Seal the inlet and outlet of the bubbler stem by connecting a piece of PTFE tubing between them or by inserting PTFE plugs in the inlet and outlet. Pack securely for shipment. If samples cannot be analyzed within four hours, they must be refrigerated at 8 °C during shipping and until analysis time. 7. Collect a bulk sample (ca. 1 g) in a glass vial with a PTFE-lined cap and ship separately.

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