Page:NIOSH Manual of Analytical Methods - 5010.pdf/2

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BROMOXYNIL and BROMOXYNIL OCTANOATE: METHOD 5010, Issue 2, dated 15 August 1994 - Page 2 of 3

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

EQUIPMENT:

Bromoxynil. Bromoxynil octanoate. Acetonitrile, HPLC grade. Water, distilled, deionized. Calibration stock solution, 1 mg/mL. Dissolve 0.100 g each of Bromoxynil and Bromoxynil octanoate in acetonitrile; dilute to 100 mL in a volumetric flask. Prepare daily, in duplicate.

1. Sampler: PTFE-coated glass fiber (Pallflex T60A20) or 2-µm PTFE membrane (GHIA), 37-mm diameter. (Filters commercially available). NOTE: Use opaque or light-protected cassette filter holder. 2. Personal sampling pump, 1 to 3 L/min, with flexible connecting tubing. 3. Jars, ointment, 60-mL, squat form, with PTFElined screw caps. 4. Volumetric flasks, 10- and 100-mL 5. Pipet, 3-mL. 6. Vials (for autosampler). 7. Liquid chromatograph with gradient capability, UV detector (254 nm) and column, (see page 5010-1). 8. Syringes, 5-mL. 9. Syringe filters, PTFE; or Swinnex adaptor with luer fitting containing 0.5-µm PTFE filter, 13-mm.

SPECIAL PRECAUTIONS: None.

SAMPLING: 1. 2. 3.

Calibrate each personal sampling pump with a representative sampler in line. Sample at an accurately known flow rate between 1 and 3 L/min for a total sample size of 20 to 400 L. Do not exceed 2 mg total dust loading on filter. After sampling, cap the filter holders, ship at 4 °C and protect from light.

SAMPLE PREPARATION: 4. 5.

Transfer the filter to a jar. Add 3.0 mL acetonitrile and desorb with occasional swirling for at least 1 h. Filter an aliquot through a PTFE syringe filter or a 0.5-µm PTFE filter using a syringe with a Swinnex adaptor to remove particulate. Transfer the aliquot to a sample vial and seal.

CALIBRATION AND QUALITY CONTROL: 6.

Calibrate daily with at least six working standards over the range 0.6 to 30 µg of both analytes per sample. a. Add known amounts of calibration stock solution to acetonitrile in 10-mL volumetric flasks and dilute to the mark. b. Analyze together with samples and blanks (steps 11 and 12). c. Prepare calibration graph (peak area vs. µg analyte). NOTE: Before processing any samples, demonstrate, through the analysis of a solvent blank, that all glassware and reagents are interference-free. Each time a new set of samples is analyzed or there is a change in reagents, process a solvent blank as a safeguard against chronic laboratory contamination. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

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