PENTAMIDINE ISETHIONATE: METHOD 5032, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS:
EQUIPMENT:
1. 2. 3.
Pentamidine isethionate, 99+% pure. Water, deionized. Ethanol, undenatured, chromatographic quality. 4. Acetonitrile, chromatographic quality. 5. Phosphoric acid, 42.5% solution. Dilute 85% solution 1:1 with water. 6. Tetramethylammonium chloride (TMAC), 10% solution. Dissolve 10.3 g of 97% pure reagent in water to make 100 mL of solution. 7. Eluent. Place 1 L of ethanol, 4 mL of 42.5% H3PO 4, and 8 mL of 10% TMAC solution into a 2-L flask. Add water to make 2 L of solution. 8. Mobile phase. Place 4 mL of 42.5% H 3PO 4 and 8 mL of 10% TMAC into a 2-L flask. Add 1608 mL of water and 392 mL of acetonitrile. 9. Recovery solutions, 1.5, 35, and 1000 ng/µL. Dissolve 25 mg of pentamidine isethionate in ethanol to make 25 mL of solution. Make serial dilutions with ethanol. Recovery solutions are stable at least 6 days in the dark at 0 °C. 10. Disinfectant. 70% Ethanol or 70% isopropanol in water.
See SPECIAL PRECAUTIONS.
SAMPLING: 1. 2. 3.
4. 5. 6.
1. Sampler: two-piece filter cassette holder (opaque), 37-mm PVC membrane filter, 5-µm pore size. 2. Personal sampling pump, 1 to 2 L/min, with flexible connecting tubing. 3. High performance liquid chromatograph with a guard column packed with Ultrasphere C8, an analytical column (Beckman Instruments) (page 5032-1), and a fluorescence detector. 4. Volumetric flasks, 2-L and 25-mL. 5. Syringes, 1- and 0.5-mL, readable to 10 µL; 10 µL, readable to 0.2 µL. 6. Beakers, 50-mL. 7. Film, plastic, flexible, water-resistant. 8. Pipets, disposable. 9. Forceps. 10. Ultrasonic bath. 11. Biological safety cabinet [3]. 12. Gloves, disposable. 13. Gauze pads.
Calibrate each personal sampling pump with a representative sampler in line. Attach the sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 1 and 2 L/min for a total sample size of 50 to 1500 L. Limit the loading of particulate matter on the filter to a maximum of about 1 mg. Seal the inlet and outlet of the sampler with plugs. Wet a gauze pad with disinfectant, and wipe the exterior surface of the sampler. Pack the sampler securely for shipment.
SPECIAL PRECAUTIONS: This method includes safety steps to minimize exposure of the analyst to tuberculosis bacteria ( Mycobacterium tuberculosis ). A fraction of the patients with acquired immunodeficiency syndrome (AIDS) have tuberculosis. Consequently, live tuberculosis bacteria may be collected during air sampling. Inhalation of tuberculosis bacteria in aerosols is the only notable means of transmission which results in infection. Infection does not result from skin contact. Thus, the analyst is safe as long as aerosols are not produced. The use of alcohol to kill tuberculosis bacteria simply increases the degree of safety.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
