Page:NIOSH Manual of Analytical Methods - 1616.pdf/3

 n-BUTYL GLYCIDYL ETHER: METHOD 1616, Issue 1, dated 15 August 1994 - Page 3 of 3

range of interest. Prepare three tubes at each of five levels plus three media blanks. a.	 Remove and discard back sorbent section of a media blank sampler. b.	 Inject known amount (1 to 20 µL) of n-butyl glycidyl ether or standard solution of n-butyl glycidyl ether in CS2 directly onto front sorbent section with a microliter syringe. 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. mg n-butyl glycidyl ether recovered. 10.	Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and DE graph are in control. MEASUREMENT: 11.	Set gas chromatograph according to manufacturer’s recommendations and to conditions given on page 1616-1. 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 CS2, reanalyze, and apply the appropriate dilution factor in calculations. 12.	Measure peak area. CALCULATIONS: 13.	Determine the mass, mg (corrected for DE) of n-butyl glycidyl ether found in the sample front and back sorbent sections, and in the average media blank front  and back  sorbent sections. NOTE:	If >  /10, report breakthrough and possible sample loss. 14.	Calculate concentration,, of n-butyl glycidyl ether in the air volume sampled, (L): , mg/m³. EVALUATION OF METHOD: Method S81 was issued on February 14, 1975 [2] and validated over the range 133 to 542 mg/m³ for 10-L air samples from dynamically generated test atmospheres [1]. The n-butyl glycidyl ether concentrations were independently measured by means of a total hydrocarbon analyzer. The average recoveries for sets of six samples taken at concentrations of 542 and 259 mg/m³ were 99.8% and 98.2%, respectively. A different method was used to generate concentrations of about 133 mg/m³. For two sets of six samples taken at the latter concentration, the average recovery was 83.9%. The reason for the low recovery was not determined. Breakthrough was not observed after sampling 44 L from a test atmosphere containing 30 mg/m³ of n-butyl glycidyl ether. The desorption efficiency decreased from 93.1 to 82.6% as loadings decreased of 6.4 to 1.6 mg per sample. Sample stability was not determined; however, refrigeration of the samples upon receipt by the laboratory is recommended. REFERENCES: [1]	 Documentation of the NIOSH Validation Tests, S81, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977). Available as GPO Stock #017-033-00231-2 from Superintendent of Documents, Washington, DC 20402. [2]	 NIOSH Manual of Analytical Methods, 2nd ed., Vol. 2, S81, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-C (1977). METHOD REVISED BY: R.A. Glaser, NIOSH/DPSE. Method S81 was originally validated under NIOSH Contract CDC-99-74-45. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition