Guo Li-feng, Yao Bo, Zhou Ling-xi, Li Pei-chang, Xu Lin
Institute of Meteorological Science of Heilongjiang Province, Harbin 150030, China.
Huan Jing Ke Xue. 2013 May;34(5):2025-30.
Custom-made GC-MS and GC-ECD in-situ measurement systems were established at the Shangdianzi GAW Regional station. From May 2010 to May 2011, the precisions for GC-MS and GC-ECD systems were 0.23% and 0.88%, respectively, and the HCFC-142b mole fraction during the observation period ranged from 21 x 10(-12) to 355 x 10(-12). The result of the independent-sample T test was P > 0.05, and there was no significant difference in HCFC-142b mole fraction measured by the two systems. The small difference of HCFC-142b mole fraction measured by GC-MS and GC-ECD might be associated with the different sampling time and precision of the two systems. A statistical filter of "robust local regression" was applied to separate HCFC-142b background and pollution data. The mean difference, median difference, 25 and 75 percent difference of background data measured by GC-MS and GC-ECD were all within the precisions. The pollution events captured by the two systems showed similar characters. Results from both systems showed a higher HCFC-142b level in summer and autumn than in winter. The pollution mole fraction of the two systems showed similar seasonal changes.
在上甸子全球大气本底站建立了定制的气相色谱-质谱联用仪（GC-MS）和气相色谱-电子捕获检测器（GC-ECD）原位测量系统。2010年5月至2011年5月期间，GC-MS和GC-ECD系统的精密度分别为0.23%和0.88%，观测期内HCFC-142b的摩尔分数范围为21×10⁻¹²至355×10⁻¹²。独立样本T检验结果为P>0.05，两个系统测量的HCFC-142b摩尔分数无显著差异。GC-MS和GC-ECD测量的HCFC-142b摩尔分数的微小差异可能与两个系统不同的采样时间和精密度有关。应用“稳健局部回归”统计滤波器来分离HCFC-142b的背景和污染数据。GC-MS和GC-ECD测量的背景数据的平均差异、中位数差异、25%和75%差异均在精密度范围内。两个系统捕获的污染事件表现出相似的特征。两个系统的结果均表明，夏季和秋季的HCFC-142b水平高于冬季。两个系统的污染摩尔分数呈现出相似的季节变化。
