摘要
汞在大气中的化学行为对全球的生物地球化学循环起着极其重要的控制作用。大气汞主要包括气态单质汞(Hg^0)、气态活性汞(Hg^(2+))和颗粒态汞。尽管颗粒态总汞(TPM)占大气总汞的5％以下，但它却是大气汞干湿沉降的主要贡献者之一，对于汞在大气中的循环演化意义重大。大气中TPM的含量在Pg·m^(-3)量级上，因此建立TPM的可靠采集与分析方法非常必要。本文利用一种新开发的小型捕集管建立了测定大气中痕量TPM的方法。实验证明，采样流速为1．0～1．5L/min时，平行样的精密度高，最低检出限为2Pg；样品经2次循环分析其热解吸效率在99％以上，分析方法非常简单和省时。
The chemical behaviors of mercury in the atmosphere play a significant controlling role in global mercury biogeochemical cycles. The main three forms of atmospheric mercury are ： Elemental gaseous mercury （Hg^0）, reactive gaseous mercury （Hg^2＋） and particulate mercury. Although total particulate mercury （TPM） only constitute less than 5% of the total mercury in the atmosphere, it is likely to govern a substantial part of the total deposition of mercury and is believed to play an important role in the atmospheric cycle of mercury. The concentrations of TPM in ambient air are in the order of picograms per cubic meter of air, so it is imperative to have reliable methods for sampling and analysis of TPM. A procedure to determine trace TPM in the atmosphere using a new miniaturized trap was set up. The precision of the parallels was generally high, when air was pulled through the trap at rates ranging from 1.0 to 1.5 L·min^-1 during sampling. The absolute detection limit of the method is below 2 pg. The thermal desorption efficiency of samples is more than 99 % through two analysis heating cycles. The operational procedures of the method are easy and time saving.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2005年第4期333-336,共4页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
国家自然科学基金(40273041)
关键词
大气
颗粒态总汞
捕集管
测定
atmospherere total particulate mercury
traps
determination
