XRF Filter Standards

Membrane and Filter Standards

NWT has supplied ion exchange membrane (soluble metal ions) and filter (solid metal oxide) standards to numerous clients including instrument manufacturers and nuclear power generation facilities. The ion exchange membrane standards are prepared by passing a solution containing soluble metals through the membranes. The filter standards are manufactured by passing a water suspension of solid metal oxides through the filters. Using this approach, a distribution comparable to actual samples is developed the membrane and the filter standards. The metal oxides on the filter standards are initially slightly radioactive. The total activity per filter standard is usually less than one µCi.

NWT has successfully prepared membrane and filter standards loaded with chromium, cobalt, copper, iron, manganese, nickel and zinc. Loadings range from approximately 0.01 to 10 mg/filter. Due to the nature of the production technique used for the filter standards, NWT employs two different approaches.  In the first approach, NWT prepares multiple standards at one time and provides a listing of available filter loadings to clients. Filter standards can then be selected to meet calibration requirements. In the second approach clients specify the filter standard loadings. However, there are limitations to the specifications which must be discussed with NWT. Although more flexibility is available relative to ion exchange membrane standard loadings, the loading is limited to the capacity of the membrane. Either Nanodex CX|200© or Toray RX-1© membrane standards can be supplied.

For more information, including pricing, contact Mike Miller at NWT at (408) 281-1100 or lab@nwtcorp.com.