| Determination of five water soluble cations, Na+, K+, Mg2+, Ca2+ and NH+4 in atmospheric particulates PM2.5 by ion chromatography was investigated. The result showed that the blank value of Quartz membrane was higher than that of Teflon membrane especially for Na+ and Ca2+ determination. The best ultrasonic time of sample pretreatment was 60 min. Correlation coefficient of standard curve of five cations were as high as 0.999 after optimizations. The determination values of the standard sample were within the guaranteed values. When the sampling volume was 20 m3 of standard conditions, the detection limit of Na+, NH+4 was 0.05 μg/m3, the detection limit of K+, Mg2+, Ca2+ was 0.1 μg/m3. On the real sample testing, the precision was lower to 1.3% and the recovery rates were between 87.5% and 109%. |
