Cd, Se, As, V, Bi, Fe, Co, Cu, Ni, Pb, Cr, Zn determination in natural, potable and waste water
The method includes coprecipitation of metals at a preset pH in the form of pirrolidinditiocarbaminate complexes (PDTC) on waxed filters.
Mass element content of dissolved forms is determined after sample material filtration, mass content of the forms summary is determined after the sample material treatment with nitric acid (decomposition). Mass content of insoluble forms is calculated as the difference between total and dissolved concentrations.
No special water treatment for reduction of interference due to composition (matrix effects) is required. Common composition concentrate on filter is the result of precipitation.
Concentrating is carried out in dynamic mode by mixing the sample material and PDTC in a mixer with further precipitation of the obtained complexes on waxed filter. Filtration is fulfilled with peristaltic pump.
After concentrating on filter the sample filter is dried, fixed in a filter holder and placed into spectrometer.
Analysis is carried out automatically according to the chosen program.
Sample preparation for determination of As, Se, Bi is carried out separately from sample preparation for Cd, Pb, Zn, Cu, Ni, Co, Fe, Cr, V determination, and only after sample decomposition. Therefore analysis of As, Se, Bi is run separately.
Acid treatment of water sample material is not run for Cr (6+) determination.
The test method specifies determination of one or several elements in dissolved form, or the sum of all forms dependent on the analysis purpose.
|Element||Mass content concentration range, mg/dm3|
|Bismuth, Lead, Zink, Nickel, Cobalt, Iron*, Vanadium, Arsenic, Selenium, Cadmium
||From 0,005 up to 0,50|
|Over 0,50 up to 5,0|
||From 0,020 up to 0,20|
||From 5,0 up to 50|
||From 0,05 up to 5,0|