上海市大气PM2.5中羰基化合物的研究

利用2,4-二硝基苯肼(DNPH)作为衍生化试剂,高效液相色谱/紫外检测法(HPLC/UV)定量检测上海市大气PM2.5中单羰基和二羰基化合物,共检测出5种单羰基化合物和2种二羰基化合物(乙二醛和甲基乙二醛).单羰基化合物中浓度最高的是甲醛和乙醛,其年平均浓度分别为(1579.47±672.81)ng/m3和(572.02±470.58)ng/m3;二羰基化合物乙二醛和甲基乙二醛的年平均浓度分别为(63.74±54.27)ng/m3和(97.28±39.62)ng/m3.研究发现上海市大气PM2.5中一些羰基化合物具有明显的日变化和季节变化规律:日变化表现为早晚高峰,而季节性变化单羰基化合物是冬天>夏天,二羰基化合物则是夏季>冬季.此外,PM2.5中羰基化合物的浓度还与温度、湿度、质量浓度具有一定的关系.

Carbonyl compounds in PM2.5 in the atmosphere of shanghai

A method for detection of carbonyl compounds in atmospheric PM2.5 in Shanghai was established by using high performance liquid chromatography (HPLC) after derivatization with 2,4-dinitrophenylhydrazine (DNPH). Five mono-carbonyl and two dicarbonyl compounds were detected in atmospheric PM2.5 samples in Shanghai. Among the mono-carbonyl compounds, formaldehyde was found to have the highest annual average concentrations at (1579.47 ± 672.81) ng/m3, followed by acetaldehyde at (572.02 ± 470.58) ng/m3. The annual average concentrations of the two dicarbonyl compounds (glyoxal and methylglyoxal) were (63.74 ± 54.27) and (97.28 ± 39.62) ng/m3, respectively. Some of the carbonyl compounds in the PM2.5 samples showed obviously diurnal and seasonal variations. The concentrations of carbonyl compounds increased during rush hours in the morning and evening. The annual average concentrations of mono-carbonyl compounds were the highest in the winter and the lowest in the summer, whereas the concentrations of dicarbonyl compounds were higher in the summer than those in the winter. In addition, the concentrations of carbonyl compounds in the PM2.5 samples were also related with the temperature, humidity, and the mass concentrations.