Size distribution evaluation of metal in surface water by filtration method

In the surface water analysis, the existing forms of iron and aluminium are apt to change during the preservation period and the filtration. The sample should be filtered within a day after the sampling and the sample volume should be small to avoid gel layer formation during filtration. Size distribution of metal in surface water was evaluated by filtration method. Sodium, potassium, calcium and magnesium are dissolved predominantly as free ions, whereas aluminium and iron are existing as particulate matters in surface water samples.