What is the difference between the determination of heavy metals in water quality and that in soil?

The determination of heavy metals in water and soil is similar in many aspects, but there are some differences. Let me explain it to you.

1. Different sampling methods:

When determining heavy metals in water, we usually need to directly determine the content of heavy metals in water samples. At this time, it is necessary to collect water samples, concentrate the heavy metals in the water to a smaller volume through specific treatment methods, and then directly determine the heavy metal content.

In order to determine heavy metals in soil, it is necessary to collect soil samples. Usually, soil samples with different depths are collected by soil drill or shovel, and then the collected soil samples are prepared and treated to extract heavy metals from the soil and determine their contents.

2. Different sample treatment methods:

For water samples, the treatment is relatively simple, and measurable samples can be obtained only by filtering, diluting or concentrating.

However, soil samples need more complicated treatment process to remove interfering substances that affect the determination. Commonly used soil sample treatment methods include acid extraction, alkalization, dissolution, ion exchange and low temperature.

3. Different instruments and equipment:

For the determination of heavy metals in water, commonly used instruments and equipment include atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP-OES) and mass spectrometer (ICP-MS).

However, the determination of heavy metals in soil requires more pretreatment steps and more complicated measuring instruments. Common determination methods of heavy metals in soil include atomic absorption spectrometry, inductively coupled plasma emission spectrometry, mass spectrometry and X-ray fluorescence spectrometry.

In a word, although the determination of heavy metals in water is similar to that in soil, there are still great differences in sample collection, processing and equipment.