The preconcentration is done by cathodic deposition at a controlled time and potential. The deposition potential is usually 0.3�C0.5 V more www.selleckchem.com/products/mek162.html negative than the standard redox potential for the least easily reduced metal ions to be determined. The metal ions reach the mercury electrode by diffusion and convection, where they are reduced and concentrated as amalgams . Inhibitors,Modulators,Libraries Typical DP voltammograms of cadmium(II) and lead(II) ions measured with HMDE using automated electrochemical analyser are shown in Figure 1. The calibration curves were strictly linear with detection limits on the order of hundreds of pM. Relative standard deviation did not exceed 2%.Figure 1.(A) DP voltammograms of lead(II) and cadmium(II) ions: a (Pb2+ 10.0 ��M, Cd2+ 10.0 ��M); b (Pb2+ 15.6 ��M, Cd2+ 25.0 ��M); c (Pb2+ 32.
3 ��M, Cd2+ 100.0 ��M); d (Pb2+ 62.5 ��M, Cd2+ 175.0 ��M); e …2.2. Electrochemical Detection of Cadmium(II) and Lead(II) Ions��PalmSens potentiostatDifferential pulse anodic stripping voltammetry using HMDE as a working electrode is among the most sensitive analytical techniques Inhibitors,Modulators,Libraries used for heavy metal ion detection. However, from a technological point of a view, the non-solid Inhibitors,Modulators,Libraries electrodes have much more lower miniaturization potential than solid electrodes, like silver, gold, carbon or platinum. The printing of electrodes is a promising technology for further miniaturization. Screen-printing is an undemanding non-vacuum method for spreading of thixotropic materials. Single layers are created by pressing the paste on the substrate through the screen.
The advantage of this technique is its simplicity, high mechanical and electric properties, easy connection to other circuits and particularly, low-cost , yet despite the many advantages of printed electrodes, their fabrication requires sophisticated technological equipment including highly professional servicing.Based on the aforementioned facts, Inhibitors,Modulators,Libraries we tested two miniaturized electrode systems, both connected to a PalmSens potentiostat, for detection of cadmium and lead ions (Figure 2). The first system uses screen-printed carbon electrodes (Figure 2A) and the second commercially available pipette tips (Figure 2B).Figure 2.Photos of screen printed carbon electrode and/or carbon tips electrode connected to PalmSens potentiostat.A pipette tip (1 ml, Tosoh, Japan) is made from polymeric material and coated by graphite.
The presence of such polymeric and carbon-based material enables us to use this accessory as Anacetrapib a working electrode, because it is of conductive resin. Based on the mentioned facts, these electrodes can be used for detection of substances undergoing reduction and/or oxidation on the surface of such electrodes without any pre-treatment procedures. We investigated dependence of cadmium(II) ions peak height on time of accumulation of these not ions on both working electrodes (SPE��screen-printed electrodes and CTE��carbon tip electrodes).