Page:NIOSH Manual of Analytical Methods - 2545.pdf/3

 ALLYL GLYCIDYL ETHER: METHOD 2545, Issue 1, dated 15 August 1994 - Page 3 of 4 b. c. 9.

10.

Analyze with samples and blanks (steps 11 and 12). Prepare calibration graph (ratio of allyl glycidyl ether peak area to internal standard peak area vs. µg allyl glycidyl ether per 2 mL). Determine desorption efficiency (DE) at least once per year for each lot of Tenax GC used for sampling in the range of interest. Determine for three samplers at each of five concentrations plus three media blanks. a. Transfer front sorbent section of media blank sampler to a 5-mL vial. b. Inject known amount (1 to 10 µL) of allyl glycidyl ether or standard solution of allyl glycidyl ether in hexane directly into sorbent in vial with a microliter syringe. NOTE: Standard solutions for DE determination should not contain internal standard. c. Cap the tube. Allow to stand overnight. d. Desorb (steps 5 through 7) and analyze with working standards (steps 11 and 12). e. Prepare a graph of DE vs. µg allyl glycidyl ether recovered. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and DE graph are in control.

MEASUREMENT: 11.

12.

Set gas chromatograph according to manufacturer's recommendations and to conditions given on page 2545-1. Inject sample aliquot manually using solvent flush technique or with autosampler. NOTE: If peak area is above the linear range of the working standards, dilute an aliquot of the desorbed liquid with diethyl ether, reanalyze, and apply the appropriate dilution factor in calculations. Measure peak areas. Divide peak area of allyl glycidyl ether by peak area of internal standard for each chromatogram.

CALCULATIONS: 13.

14.

Determine the mass, µg (corrected for DE) of allyl glycidyl ether found in the sample front (W f) and back (W b) sorbent sections, and in the average media blank front (B f) and back (B b) sorbent sections. Note: If W b > W f/10, report breakthrough and possible sample loss. Calculate concentration, C, of allyl glycidyl ether in the air volume sampled, V (L):

EVALUATION OF METHOD: Method S346 was issued on January 21, 1977 [2] and was validated over the range 19 to 87 mg/m 3 for 3-L air samples from dynamically generated test atmospheres [1]. The average recoveries ranged from 98.2 to 99.5%. The allyl glycidyl ether concentrations were independently calculated from analyte delivery rate and air dilution ratios. Breakthrough was observed after sampling 12 L from a test atmosphere containing 87 mg/m 3 of allyl glycidyl ether at 90% relative humidity. Desorption efficiency ranged from 101% to 89.8% for loadings of 67 to 269 µg allyl glycidyl ether per sample. A storage stability study gave average recoveries of 96.9% for 7-day storage versus 98.1% for 1-day storage.

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