Characterization of air particulate matters and elements in four national background locations,China

PM10and PM2. 5samples were collected from four national background locations(Nanling,Shennongjia,Pangquangou and Changbaishan) during four seasons in 2013. More than 60 elements in PM10 and PM2. 5were analyzed by microwave-assisted digestion and inductively coupled plasma mass spectrometry(ICP-MS). The results showed that the average daily mass concentrations of PM2. 5and PM10 from four sites were 17 μg·m- 3and 29 μg·m- 3respectively,which are lower than the air quality standards in China(GB 3095—2012). The mass concentrations of PM10 and PM2. 5in seasonⅠ were higher than the other three. Except season Ⅲ Ⅳ in Changbaishan,the mass concentrations of PM10 and PM2. 5were quarterⅡ Ⅳ Ⅲ in other three background locations. The correlation analysis by linear regressive equation showed there was positive correlation between PM2. 5and PM10.The ratios of PM2. 5/ PM10 were lower than 0. 5,of which seasonⅡ and Ⅲ were higher than seasonⅠ and Ⅳ. The element concentrations in PM2. 5were lower than those in PM10,both of which changed little during four seasons. The concentrations of Na,Mg,Al,S,K,Ca Fe and Zn were in the range of 0. 1—10 μg·m- 3; P,Ti,Mn,Ni,Cu,Ba and Pb 10—100 ng·m- 3; Cd,Co,Ge,Ga,Zr,Sr and V 0. 01—10 ng·m- 3. The contents of K,Al,Ca were more than 10%. Thecontents of S,Mg,Na,Fe,Zn,Pb and Mn were above 1%. The contents of Cu,P,Ba and Ti ranged in 0. 5% —1%. The contents of other trace element were lower than 0. 5%.