METHYL ACRYLATE: METHOD 1459, Issue 1, dated 15 August 1994 - Page 3 of 3
10.
c. Cap the tube. Allow to stand overnight. d. Desorb (steps 5 through 7) and analyte together with working standards (steps 11 and 12). e. Prepare a graph of DE vs. µg analyte recovered. Analyze three quality control blind spikes and three analyst spikes to insure 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 1459-1. 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 with eluent, reanalyze and apply the appropriate dilution factor in calculations. Measure peak area. Divide the peak area of analyte by the peak area of internal standard on the same chromatogram.
CALCULATIONS: 13.
14.
Determine the mass, µg (corrected for DE) of analyte 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, analyte in the air volume sampled, V (L):
EVALUATION OF METHOD: Method S38 for methyl acrylate was issued on 12/6/74, and evaluated over a range of 13.9 to 58.4 mg/m 3 at an atmospheric temperature of 23°C and a pressure of 764 mm Hg, using 6-L samples [1]. Breakthrough was determined by sampling a generated atmosphere at a concentration of 59 mg/m 3 for 240 min at a flow rate of 0.190 L/min. Desorption efficiency (DE) was determined by spiking charcoal tubes at three levels, 0.087, 0.175, and 0.350 mg of methyl acrylate. Desorption efficiencies were 0.810, 0.785, and 0.841, respectively. The measurement precision ( Sr) was 0.049, and the overall precision, including pump error, was 0.066. The mean bias for samples generated at three concentration levels (0.5, 1 and 2 x PEL) was -10.4%, resulting in an overall accuracy of ± 23.3%. Sample storage stability was not determined. REFERENCES: [1] [2] [3] [4]
[5]
Documentation of NIOSH Validation Tests, NIOSH Contract No. CDC-99-74-45. NIOSH Manual of Analytical Methods, 2nd ed., V. 2, S38, U.S. Department of Health, Education, and Welfare, Publ (NIOSH) (1978). NIOSH Manual of Analytical Methods, Second Edition Method Update Information, (1990). A. Horna, Taborsky J., Churacek J., and Dufka O. "IV. Gas-liquid Chromatographic Studies of C1 - C 6 n-Alkyl and C 3 - C 6 isoalkyl acrylates and their hydrogen halide and halogen addition derivatives," J. Chromatogr., 348(1), (1985). N. Gjoes, et al. "Identification of Methyacrylates by Mass Spectrometry," Anal. Chem. Acta, 149, 87-99 (1983).
METHOD WRITTEN BY: Jim Xue, NIOSH, DPSE.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
