US EPA

4120272 

Journal Article 

Determination of Maleic Anhydride in Workplace Air by Reversed-Phase High-Performance Liquid Chromatography 

Geyer, R; Saunders, GA 

1986 

1 

Journal of Chromatography
ISSN: 0021-9673 

NIOSH/00164844 

368 

2 

456-458 

An improvement of the current NIOSH high performance liquid chromatography (HPLC) procedure for analyzing airborne maleic-anhydride (108316) was described, which uses a simpler mobile phase, 0.1 percent phosphoric-acid in distilled water. The mobile phase was also used as the absorbing solution to collect the airborne maleic-anhydride. This mobile phase suppressed the ionization of maleic-acid sufficiently for the carboxylic-acid to have adequate retention of the reversed phase column. At a flow rate of 0.7 milliliters/minute, maleic-acid had a retention time of 3.2 minutes and was baseline separated from its structural isomer, fumaric-acid, which had a retention time of 4.7 minutes. The run time for the analysis was 5 minutes compared with over 8 minutes for the current NIOSH HPLC procedure. The conversion of maleic-anhydride to maleic-acid in the mobile phase was quantitative at the 0.05, 0.10, and 0.20 milligram (mg) levels. The relative standard deviation for injection of the 0.05, 0.10 and 0.20mg/15milliliters (ml) maleic-anhydride standards was 3.3, 1.5, and 1.9 percent, respectively. A chromatogram was presented of an air sample taken while an operator in a paint factory was adding maleic-anhydride to a polyester resin kettle. The linearity of the detector response for maleic-anhydride, measured as maleic-acid, was confirmed in the range 0.05 to 0.20mg/15ml standard solution.