| Based on epidemiological studies, atmospheric particulate matter(PM), especially atmospheric fine particulate matter(PM2.s) had adverse health impacts on cardiopulmon ary system disease, which was caused by particle size, chemical composition of PM2.5and the body fluid environment. The transition metals and quinones, as important c omposition of PM2.5, could induce oxidative stress and produce reactive oxygen speci es (ROS) in cellular system. Hydrogen radicals(·OH) have high reactivity and couldn’ t be removed by related enzymes in vivo, so hydrogen radicals are considered to be the most important component of ROS, which could induce biological damage.In the present study, Fe,1,2-naphthoquinone(1,2-NQN),1,4-benzoquinone(1,4-BQ N) and9,10-phenanthrenequinone(9,10-PQN) were chosen as modulate to simulate the mechanism of·OH generation in a cell-free surrogate lung fluid which contains four antioxidants:ascorbic acid, citric acid, glutathione and uric acid. We established a d etection method for determination of hydrogen radical with benzoic acid salt (BA) as probe in42hours.The minimum detection concentration for p-HBA was0.0152μM (LOD=3SN/m) and the lowest concentration for hydrogen radicals was0.0739μM.·O H generation induced by Fe and quniones was quantitatively determined in a cell-free surrogate lung fluid which contains four antioxidants and the effect of four antioxid ants on·OH generation was deeply studied; The results proved that combined inducti on of Fe,1,2-NQN,1,4-BQN and9,10-PQN could have influence on hydrogen radic als generation.Secondly, samples of PM2.5in Guangzhou were collected and two different sourc es PM2.5samples:vehicle exhaust and dining lampblack, respectively. The influence o f·OH generation by sampling material was analyzed. By comparing·OH generation from different source of PM2.5, PM2.5in the city and in the country and PM2.5sampl es in winter and summer, it was found that quartz membrane had certain interference on·OH formation.·OH generation from automobile exhaust particles was more than dining lampblack particles;·OH generation had obvious positive correlation with PM2.5concentrations; Compared the·OH reaction rate, Guangzhou (urban) PM2.5was fa ster than Guangzhou (rural) PM2.5. In addition, the main chemical composition of PM2.5(including water soluble me tal ions and quinones) were analyzed. The water soluble metal ions and the total met al ions from different source of actual PM2.5samples were tested by ICP-MS. The w ater soluble metal ions and the total metal ions from different source of actual PM2.5samples were tested by ICP-MS. The results showed that the order of the water sol uble metal ion content in PM2.5samples was:Fe>Mn>V>Pb>Ni>Cd>Co, Cu、Cr、Zn water soluble ion content were below the detection limit. Therefore, Fe has the highe st concentration in PM2.5samples.Finally, a quantitative analysis method in order to detect1,2-NQN,1,4-BQN and9,10-PQN three major quinones in actual PM2.5samples was established by gas chro matography(HP6890GC)/mass spectrometry (HP5972MS). The minimum detection cone entration is10ppb (LOD=3SN/m). Three samples of quinones in Guangzhou PM2.5w ere analyzed and found that9,10-PQN>1,4-BQN>1,2-NQN. Therefore, quinones were also the main components of PM2.5.Based on the study, it can be concluded that:Fe may certainly place a premium on the·OH generation; Asc and Cit can promote the generation of·OH; The con centration of PM2.5in Guangzhou city had positive correlation with·OH;·OH gen erated from automobile exhaust particles more than dining lampblack practical PM2.5samples;·OH was combined induced by metal ions and quinone materials (1,2-NQ N、1,4-BQN、9,10-PQN) and cause cellular damage. |
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