IC Determination of Sulfur Dioxide and Nitrogen Dioxide in Environmental Air of Museum with Passive Sampling

In the passive sampling of sulfur dioxide and nitrogen dioxide from environmental air of museum, a portion (100 μL) of mixed absorption solution, composed of w_S 20% of TEA, w_S 10% of glyoerin and w_S 1% of sodium hypophosphite, was added to the absorption film of the cleaned and dried samplers, which were placed at definite sites for a sampling time of 3-5 d. At the end of sampling, the base films and absorption films were taken out and each set of the films were extracted ultrasonically for 10 min with 5.00 mL of water, and 4 anions of NO₂^-, NO₃^-, SO₃^2- and SO₄^2- in the extracts were determined by ion chromatography. IonPac AS18 chromatographic column was used for chromatographic separation, 25 mmol·L^-1 potassium hydroxide solution was used as mobile phase, and restraining conductance detector was used in the determination. The detection limits (3S/N) of the 4 anions found were 0.007 8, 0.008 9, 0.009 0, 0.008 0 mg·L^-1 respectively. Values of recovery found by standard addition method were in the range of 91.0%-103%. Values of RSD's (n=6) found were 2.5% (for NO₂^-), 22% (for NO₃^-), 21% (for SO₃^2-), 29% (for SO₄^2-).