Page:NIOSH Manual of Analytical Methods - 1551.pdf/3

 TURPENTINE: METHOD 1551, Issue 2, dated 15 August 1994 - Page 3 of 3 a. b.

10.

Remove and discard back sorbent section of a media blank sampler. Inject a known amounts of the turpentine bulk sample 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 together with working standards (steps 11 and 12). e. Prepare a graph of DE vs. mg turpentine 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 1551-1. 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. NOTE: Compare chromatograms of the air samples and the turpentine bulk sample for evidence of qualitative differences and possible interferences.

CALCULATIONS: 13.

14.

Determine the mass, mg (corrected for DE) of turpentine 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 turpentine in the air volume sampled, V (L):

EVALUATION OF METHOD: Method S88 [3] was issued on March 14, 1975, and validated over the range 264 to 1107 mg/m 3 at 24 °C and 766 mm Hg using 10-L air samples [1]. Turpentine oil, double rectified (Fisher Scientific Co.; BP 150 to 170 °C; d 0.868 g/mL) in a calibrated syringe drive was used to generate turpentine atmospheres in dry air. Overall precision, SˆrT, was 0.055 with average recovery of 99%, representing a non-significant bias. Desorption efficiency was 0.95 in the range 2.8 to 11.3 mg per sample. The chromatographic column used was 6 ft x 1/8 in stainless steel packed with 1.5% OV-101 on 100/120 mesh Chromosorb W. Breakthrough (5% on back section) occurred at 126 min when sampling an atmosphere containing 1107 mg/m 3 turpentine at 0.19 L/min at 0% RH. REFERENCES: [1] [2] [3]

Documentation of the NIOSH Validation Tests, S88, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977). User check, UBTL, NIOSH Sequence #4121-O,P (unpublished, December 2, 1983). NIOSH Manual of Analytical Methods, 2nd ed., V. 2., S88, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-B (1977).

METHOD REVISED BY: Ardith A. Grote, NIOSH/DPSE; S88 originally validated under NIOSH Contract CDC-99-74-45.

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