OBJECTIVEFour kinds of acids (acetic acid, propionic acid, acrylic acid and methylacrylic acid) in the air in a workplace were quantitatively determined by gas chromatography synchronously.

METHODSFour acids in the air were adsorbed by silica gel tube sampling and solvent desorption using acetone, then analyzed by GC with FFAP capillary column.

RESULTSTo acetic acid, propionic acid, acrylic acid and methylacrylic acid, the linear regression equations were respectively y = -4.3+1.46x (r = 0.999), y = 0.4+2.37x (r = 0.999), y = 10.4+1.73x (r = 0.999) and y = -2.3+3.21x (r = 0.999). The detection limits were respectively 3.4 microg/mL, 2.1 microg/mL, 2.9 microg/mL and 1.6 microg/mL. The average desorption efficiencies were respectively 92.2%-92.8%, 94.1%-97.4%, 94.8%-95.4% and 94.1%-98.3%. The relative standard deviations were 1.1%-4.0%, 1.2%-7.8%, 0.9%-4.0% and 1.6%-4.8%.

CONCLUSIONThe method is suitable to determine four kinds of acids in the air in a workplace.