Measuring dissolved metals in water is primarily achieved by separating the dissolved components from any solid particles before analysis.
According to standard methodology, dissolved metal concentration is determined by filtering a water sample through a 0.45 µm filter. The water that successfully passes through this filter is then collected. This filtered water (known as the filtrate) is considered to contain the dissolved metals.
Here's a breakdown of the process:
- Sample Filtration: A representative water sample is carefully passed through a 0.45 µm filter. This specific pore size is widely used to differentiate between dissolved substances and particulate matter suspended in the water.
- Filtrate Collection: The water that flows through the 0.45 µm filter is collected. This collected water is the fraction designated for dissolved metal analysis.
- Metal Analysis: The collected filtrate is then analyzed for its metal content using appropriate analytical techniques. The result obtained from analyzing this filtered water is reported as the dissolved metal concentration.
This filtration step is critical because it ensures that only metals present in the truly dissolved or very finely colloidal state are measured, excluding metals bound to larger suspended particles.
