MALEIC ANHYDRIDE: METHOD 3512, Issue 1, dated 15 August 1994 - Page 3 of 3 MEASUREMENT: 11. 12. 13.
Set liquid chromatograph to conditions given on page 3512-1. Inject 50-µL sample aliquot. Measure peak area.
CALCULATIONS: 14. 15.
Read mass, µg, of maleic anhydride (W) found in the sample from the calibration graph. Calculate concentration of maleic anhydride in the actual air volume, V (L), at the sampling site:
EVALUATION OF METHOD: This method was validated over the range 0.50 to 2.14 mg/m 3 at 20 °C and pressure of 757 mm Hg using 360-L samples [1,2]. Overall sampling and measurement precision, SˆrT, was 0.063, with a bias of - 6.7%. Recovery of maleic anhydride was 104% in the range of 181 to 723 µg maleic acid per sample. Sample stability during storage was evaluated at 367 µg per sample. Samples showed an average loss of 13% after seven days of storage at ambient conditions compared to one-day old samples. Refrigeration of samples may retard loss but this has not been experimentally determined.
REFERENCES: [1] [2] [3] [4] [5]
Backup Data Report for Maleic anhydride, prepared under NIOSH Contract 210-76-0123 (1977). NIOSH Manual of Analytical Methods, 2nd. ed., V. 5, P&CAM 302, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 78-175 (1978). Geyer, R. and Saunders, G. A. Determination of Maleic Anhydride in Workplace Air by Reverse Phase HPLC, J. Chromatogr. , 368 (2), 456-458 (1986). Kallio, H. Determination of Trace Concentrations of Maleic Anhydride in Workplace Air, Khig. Zdraveopaz , 32 (3), 86-94 (1989). NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, Department of Health and Human Services, Publ. (NIOSH) 81-123 (1981), available as GPO Stock
- 017-033-00337-8 from Superintendent of Documents, Washington, DC 20402.
METHOD REVISED BY: M.J. Seymour, NIOSH/DPSE.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
