ISO 12846:2012规定了两种在适当预消化后测定饮用水、地表水、地面水、雨水和废水中汞的方法。对于第一种方法，通过汞在例如金/铂吸附器上的融合进行富集。对于第二种方法，省略了富集步骤。 方法的选择取决于可用的设备、基质和感兴趣的浓度范围。两种方法均适用于水中汞的测定。富集法的实际工作范围通常为0.01μg/l至1μg/l。验证试验参与者报告的平均定量限（LOQ）为0008μg/l。 LOQ上的这些信息为ISO 12846:2012的用户提供了一个方向，并不能取代实验室特定数据的性能数据估计。必须考虑到，使用特定仪器（例如单汞分析仪）可以实现较低的LOQ。 未经富集的方法通常具有从0.05μg/l开始的实际工作范围。验证试验参与者报告的LOQ为0024μg/l。根据具体应用，由用户决定是否通过省略富集步骤和/或稀释样品来确定较高浓度。这两种方法的灵敏度取决于选定的操作条件。 另一种无需预浓缩即可测定低至0002μg/l的极低汞浓度的方法是应用原子荧光光谱法（见ISO 17852）。特定的原子吸收汞分析仪允许在无需预浓缩的情况下进行低至0010μg/l的测定。 一般来说，通过AAS（或AFS）测定痕量汞浓度取决于实验室的清洁操作条件，以及使用高纯度的化学品和可忽略的低汞空白。 请注意，ISO 12846:2012可适用于在适当条件下进行额外消化步骤后以及在适当方法验证后的工业和城市废水。 必须彻底考虑厌氧还原工业废水的潜在样品稳定性问题（汞损失）。

ISO 12846:2012 specifies two methods for the determination of mercury in drinking, surface, ground, rain and waste water after appropriate pre-digestion. For the first method, an enrichment step by amalgamation of the Hg on, for example, a gold/platinum adsorber is used. For the second method, the enrichment step is omitted. The choice of method depends on the equipment available, the matrix and the concentration range of interest. Both methods are suitable for the determination of mercury in water. The method with enrichment commonly has a practical working range from 0,01 μg/l to 1 μg/l. The mean limit of quantification (LOQ) reported by the participants of the validation trial was 0,008 μg/l. This information on the LOQ gives the user of ISO 12846:2012 an orientation and does not replace the estimation of performance data from laboratory specific data. It has to be considered that it is possible to achieve lower LOQs with specific instrumentation (e.g. single mercury analysers). The method without enrichment commonly has a practical working range starting at 0,05 μg/l. The LOQ reported by the participants of the validation trial was 0,024 μg/l. It is up to the user, based on the specific application, to decide whether higher concentrations are determined by omitting the enrichment step and/or by diluting the sample(s). The sensitivity of both methods is dependent on the selected operating conditions. Another possibility for the determination of extremely low Hg concentrations down to 0,002 μg/l without pre-concentration is the application of atomic fluorescence spectrometry (see ISO 17852). Specific atomic-absorption mercury analysers allow determinations down to 0,010 μg/l without pre-concentration. In general, the determination of trace concentrations of Hg by AAS (or AFS) is dependent on clean operating conditions in the laboratory and on the use of high-purity chemicals with negligible low-Hg blanks. Note that ISO 12846:2012 may be applied to industrial and municipal waste water after an additional digestion step performed under appropriate conditions and after suitable method validation. A potential sample stability issue (mercury loss) for anaerobic reducing industrial effluents has to be considered thoroughly.