This paper describes the application of a method for the direct speciation of Hg in sediment samples by thermal desorption using a Direct Mercury Analyzer®. The different thermal behavior of the Hg species allowed direct chemical speciation by DMA. The set of temperature steps was as follows: 50 °C, 100 °C, 150 °C, 200 °C, 250 °C, 300 °C, 400 °C, 500 °C, 600 °C and 700 °C. Sediment samples presented total Hg concentrations varying over a range of 36 to 1996 μg·kg⁻¹, with 78% of the samples being over of the TEL (threshold effect level). According to the speciation analysis, a prevalence of oxidized Hg was observed. This method was efficient, simple and adequate for determining the Hg speciation in sediment samples. The great advantage is that the method does not require pretreatment of the samples, and it is applicable to homogeneous solid samples.

本文介绍了使用Direct MercuryAnalyzer®通过热脱附对沉积物样品中的汞进行直接形态分析的方法的应用。汞物种的不同热行为允许通过DMA直接进行化学形态分析。该组温度步骤如下：50℃，100℃，150℃，200℃，250℃，300℃，400℃，500℃，600℃和700℃。沉积物样品的总汞浓度在36至1996μg·kg ^-1范围内变化，其中78％的样本超过了TEL（阈值影响水平）。根据形态分析，观察到氧化的Hg的流行。该方法有效，简便且足以测定沉积物样品中的汞形态。最大的优点是该方法不需要样品的预处理，并且适用于均质的固体样品。