Automation of 99Tc extraction by LOV prior ICP-MS detection: Application to environmental samples

• Automated, rapid and selective method for 99Tc extraction/preconcentration was developed.
• A Lab-On-Valve system allows saving reagents, time and cost per analysis.
• LOV system performs a sample clean-up prior to detection by ICP-MS of 99Tc.
• With the proposed analyzer it is possible to determine 99Tc at environmental levels.
• High sensitivity and selectivity are achieved, reaching the EPA regulations for 99Tc.

A new, fast, automated and inexpensive sample pre-treatment method for 99Tc determination by inductively coupled plasma-mass spectrometry (ICP-MS) detection is presented. The miniaturized approach is based on a lab-on-valve (LOV) system, allowing automatic separation and preconcentration of 99Tc. Selectivity is provided by the solid phase extraction system used (TEVA resin) which retains selectively pertechnetate ion in diluted nitric acid solution. The proposed system has some advantages such as minimization of sample handling, reduction of reagents volume, improvement of intermediate precision and sample throughput, offering a significant decrease of both time and cost per analysis in comparison to other flow techniques and batch methods. The proposed LOV system has been successfully applied to different samples of environmental interest (water and soil) with satisfactory recoveries, between 94% and 98%. The detection limit (LOD) of the developed method is 0.005 ng. The high durability of the resin and its low amount (32 mg), its good intermediate precision (RSD 3.8%) and repeatability (RSD 2%) and its high extraction frequency (up to 5 h−1) makes this method an inexpensive, high precision and fast tool for monitoring 99Tc in environmental samples.