Water analysis

X-ray fluorescence analysis (XRFA) is one of the methods applied for element concentration determination of water objects. The material for analysis may vary from potable water to sea water, from snow to wastewaters. The advantage of this method is simplicity of determination of multi elemental composition in one sample, low consumption of auxiliary materials,

The following problems may be solved with XRFA:
- determination of dissolved and not solved metal forms in water, as well as their total content;
- element content in suspensions;
- element content in snow.

Element content can  be determined either directly or after concentration dependent on the type of sample material.

Direct determination of element content by XRFA begins from first mg/L in the range from Mg up to U.

In case of direct determination the sample material is filtered from suspension and mechanical impurity, and then poured in a sample cup, placed into spectrometer. Analysis is carried out according to the chosen program automatically. No additional sample preparation is required.
Elements of the suspension are determined after concentration on membrane filter. Water sample material is pumped through the membrane filter; the filter is dried, fixed in a filter holder and placed into spectrometer. Sensitivity of analysis is first micrograms per filter, therefore it is possible to determine element content of 1-5 microgram/l after concentration of one liter of water sample material.
Heavy metal determination is usually carried out after concentration because of low content of heavy metals in  water objects.

There are two types of concentrating procedures offered:
Sorption concentrating with cellulose filters.
Sample material is pumped through the filter with sedimented aminocarboxylic groups at a preset speed. Heavy metals from the water material are fixed inside the filter. The filter is dried, fixed in a filter holder and placed into a spectrometer. When total element forms are determined, nitric acid is added to the sample, and then it is evaporated to wet salts state, which are solved further on in distilled water and pumped through the filter.
This type of concentrating is usually used for potable water, because the filter has limited sorption capability.

Sedimentation of  metal organic complex on filter.
The sample material is mixed with ammonium pirrolidinditiocarbaminate in dynamic regime. Obtained insoluble complexes are precipitated on paraffin filter. After concentrating on filter the sample filter is dried, fixed in a filter holder and placed into spectrometer. When total element forms are determined, nitric acid is added to the sample, and then it is evaporated to wet salts state, which are solved further on in distilled water and pumped through the filter.