PHENOL: METHOD 3502, Issue 2, dated 15 August 1993 - Page 3 of 3 d. e.
Analyze the working standards and blanks under the same GC conditions and during same time period as samples. Prepare a calibration graph by plotting peak area vs. µg phenol in the 25 mL volume.
MEASUREMENT: 11. 12. 13.
Set gas chromatograph according to manufacturer's recommendations and to conditions given on page 3502-1. Inject a sample aliquot using solvent flush technique. Make duplicate injections of samples and standards. Measure peak area. Clean the glass inlet on the GC at the end of each day with water and acetone rinses. Reinsert the glass inlet into the injection port and let it bake out overnight.
CALCULATIONS: 14. 15.
Read the mass (µg) of phenol found in the sample bubbler (W) and average blank bubblers (B) corresponding to each peak area from the calibration graph. Calculate concentration, C (mg/m 3), of phenol in the air volume sampled, V (L):
EVALUATION OF METHOD: Method S357 [2] was issued on August 1, 1975, and validated over the range 9.46 to 37.8 mg/m 3 at 22 °C and 760 mm Hg, using a 100-L sample [1]. Overall precision, SˆrT, was 0.068, determined by sampling and analyzing generated atmospheres containing 9.46, 18.9 and 37.8 mg/m 3 phenol in air. The concentrations were determined from the delivery rate of the syringe drive pump and the flow rates of the dilution air (20.1 L/min). The collection efficiency of the bubbler was determined at 37.8 mg/m 3 and found to be 1.00 + 0.01. No concentration changes occurred after five days storage of six samples of 15 mL 0.1 N sodium hydroxide in 25-mL volumetric flasks spiked with 1.9 mg phenol. Recovery at the OSHA standard level was 97.4%; this was not considered to be a significant bias.
REFERENCES: [1] [2] [3] [4]
Documentation of the NIOSH Validation Tests, S330, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977). NIOSH Manual of Analytical Methods, 2nd. ed., V. 3, S330, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-C (1977). UBTL Memorandum, Analytical Laboratory Report for Phenol, Sequence #2660-N and 2340-J (December 8, 1980 and June 25, 1980). Criteria for a Recommended Standard...Occupational Exposure to Phenol, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 76-196 (1976).
METHOD REVISED BY: Julie R. Okenfuss, NIOSH/DPSE; S357 originally validated under NIOSH
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/93
