Page:NIOSH Manual of Analytical Methods - 5030.pdf/2

 CYANURIC ACID: METHOD 5030, Issue 2, dated 15 August 1994 - Page 2 of 4 EQUIPMENT:

REAGENTS: 1. 2. 3. 4. 5. 6.

7.

8.

Cyanuric acid, ≥98% pure.* Water, distilled. Methanol, chromatographic quality.* Na 2HPO 4·7H 2O, reagent grade. HCl, 1 M (aqueous). Eluent and mobile phase: 0.005 M Na 2HPO 4, 5:95 (v:v) methanol:water at pH = 7.0. Dissolve 5.36 g of Na 2HPO 4·7H 2O in 2000 mL water. Add 200 mL methanol. Add water until total volume is 3990 mL. Add 1 M HCl until pH is 7.0. Calibration stock solution, 1 mg/mL. Dissolve 25 mg cyanuric acid in eluent to make 25 mL solution. Prepare fresh monthly. NOTE: Ultrasonic bath will facilitate dissolution of cyanuric acid. Recovery stock solution, 1.7 µg/µL. Dissolve 42.5 mg cyanuric acid in water to make 25 mL solution. NOTE: Ultrasonic bath will facilitate dissolution of cyanuric acid.



See SPECIAL PRECAUTIONS.

1. Sampler: 37-mm, 5-µm polyvinyl chloride (PVC) membrane filter in 2-piece cassette filter holder. 2. Personal sampling pump, 1 to 3 L/min, with flexible connecting tubing. 3. High performance liquid chromatograph (HPLC), UV absorption detector, 225 nm, recorder, intergrator and column (page 5030-1). 4. Vials, 4-mL, with PTFE-lined caps. 5. Volumetric flasks, 25-mL. 6. Carboy, 4-L. 7. Graduated cylinders, 1-L, readable to 10-mL; 250-mL, readable to 2 mL. 8. Syringes, 500-µL, readable to 10 µL; 100-µL, readable to 1 µL; 10-µL, readable to 0.1 µL. 9. Beakers, 50-mL, internal diameter ≥37 mm. 10. Ultrasonic water bath. 11. Film, plastic, flexible, water-resistant. 12. Filter units, 25-mm PTFE membrane, 0.45-µm pore size, in polypropylene housing. 13. Vacuum oven. 14. Tweezers. 15. pH meter. 16 Adhesive tape.

SPECIAL PRECAUTIONS: Cyanuric acid is a possible tumorigenic agent and a slight eye irritant [3,4]. Methanol is toxic. Ingestion of methanol may cause blindness or death. Methanol is a fire hazard (flash point 12 °C).

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 1 and 3 L/min for a total sample size of 10 to 1000 L. Limit the maximum loading of particulate matter on the filter to about 1 mg. Seal the ends of the sampler with plugs. Pack securely for shipment.

SAMPLE PREPARATION: 5. 6.

7.

Place the PVC filter face down into a 50-mL beaker (the filter should lie flat on the bottom of the beaker). Retain the cassette filter holder (step 9). Add 3 mL eluent to the beaker. Seal the mouth of the beaker with plastic film. NOTE: The volume of 3 mL is sufficient when the quantity of cyanuric acid on the filter is 1 mg or less. The limit of solubility of cyanuric acid in eluent is about 2 mg/mL at room temperature. Place the beaker into an ultrasonic bath for 10 min. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94