We want to determine heavy metal concentrations in a synthetic matrix, our requirement is a reliable and conventional procedure to find these metal levels in water, with no advance electrodes or extravagant preparation method of the analyte.
Yes, by stripping voltammetry. You need a polarographic stand Radiometer Analytical (TraceLab 50) or Metrohm (Computrace) or Amel or similar.
Some screen printed electrodes, used with small potentiostats are also available, but for higher detection limits.
Dear Cornel Radu
Many thanks for your answer. My Project's budget is insufficient. So I can not buy nor prepare a polarographic stand. I have access to an Atuolab instrument. But this instrument hasn't any electrode. I want to buy some solid electrodes, for instance, Ag-AgCl as a reference, Platinum as a counter electrode and glossy carbon as a working electrode. Do you think this setup of electrodes works well for heavy metal detection? What type of techniques may fit our requirements, with consideration of above restrictions? Thank you for spending your time.
See in the attached paper , in Fig. 2A and 2B for comparison , the experimental design with screen printed electrodes, but also with common electrodes. You may obtain , via Metrohm, dedicated SPE from DropSense. The idea is to use carbon electrodes (as WE), conditioned by in situ depositing Hg or Bi, for heavy metal analysis.
Hi Mohammad,
Yes, it is possible. As Cornel commented, you can use your Autolab and disposable SPEs from DropSens. Another possibility is using low-cost transparency films as in our manuscript (attached). Linear dynamic range for Pb and Cd: 1 to 200 ppb. (I am having problems in attaching it. In case I can't, the ref is: Anal. Chim. Acta 981 (2017) 24-33).
Good luck!
Mohammad,
I am sorry that I missed your posting earlier. It sounds like you already have some good advice from knowledgeable people. Carbon electrodes are really the preferred choice for a solid electrode onto which one can deposit a fine film of mercury for anodic stripping voltammetry. Your comment suggested that you were also considering buying a Ag/AgCl reference electrode. That is one thing that you can save on by making it yourself, if you already have some Ag wire. The wire can be coated with AgCl by attaching it to the positive end of a 1.5 V battery and immersing part of it in 0.1 M HCl. Attach the negative end of the battery to a (1-1000 Ω) variable resistor and then a Pt or C electrode. Start with the maximum resistance and after placing this electrode into the HCl solution with the Ag wire, lower the resistance gradually until very small bubbles of hydrogen gas form at the negative electrode. A coating of AgCl should be visible on the Ag electrode in 10-15 minutes. Remove the electrodes and rinse with deionized water. Shorten the tip of a Pasteur pipet and fill the tapered end with hot agar solution containing 1 M KCl. Cool the agar to room temperature and add 1 M KCl (no agar) to the inside of the pipet and place the AgCl-coated silver wire inside. This electrode should have a reference potential of +0.228 V vs a Standard Hydrogen Electrode.
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