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Amperometric signal

In this automatic system, the authors preferably used coulometric generation of titrant (cf., microcoulometric determination of deviations in the above end-point titration ), e.g., H, OH, Ag, Hg2+, Br2,12, Fe(CN) (cf., Table 1 in ref. 63). The detection method may be potentiometric (logarithmic signal), amperometric (linear signal), biamperometric, conductometric, oscillometric, etc. Moreover, the authors evaluated triangle programmed titration curves by... [Pg.347]

The applied potential affects not only the sensitivity and signal-to-noise characteristics but also die selectivity of amperometric measurements. In general, a lower potential is more selective, and a higher one more universal. Thus, compounds undergoing redox potentials at lower potentials can be detected with greater selectivity. The selection of die applied potential relies on the construction of... [Pg.87]

MWNTs favored the detection of insecticide from 1.5 to 80 nM with a detection limit of InM at an inhibition of 10% (Fig. 2.7). Bucur et al. [58] employed two kinds of AChE, wild type Drosophila melanogaster and a mutant E69W, for the pesticide detection using flow injection analysis. Mutant AChE showed lower detection limit (1 X 10-7 M) than the wild type (1 X 10 6 M) for omethoate. An amperometric FIA biosensor was reported by immobilizing OPH on aminopropyl control pore glass beads [27], The amperometric response of the biosensor was linear up to 120 and 140 pM for paraoxon and methyl-parathion, respectively, with a detection limit of 20 nM (for both the pesticides). Neufeld et al. [59] reported a sensitive, rapid, small, and inexpensive amperometric microflow injection electrochemical biosensor for the identification and quantification of dimethyl 2,2 -dichlorovinyl phosphate (DDVP) on the spot. The electrochemical cell was made up of a screen-printed electrode covered with an enzymatic membrane and combined with a flow cell and computer-controlled potentiostat. Potassium hexacyanoferrate (III) was used as mediator to generate very sharp, rapid, and reproducible electric signals. Other reports on pesticide biosensors could be found in review [17],... [Pg.62]

Due to the broad substrate specificity of AP, and the drive for higher efficiency, several studies have recently investigated the suitability of alternative substrates to the common 4-APP [47, 48], For example, Pemberton et al. compared 4-APP and 1-naphthyl phosphate (1-NP) as AP substrates in an amperometric immunosensor for progesterone [47], The signal generation scheme when 1-NP is used as a substrate is illustrated in Scheme 2. [Pg.155]

Electrolytic efficiency should therefore be <20% for optimum signal-to-noise ratio amperometric detection... [Pg.32]

Most compounds can be detected directly as they are able to produce a direct analytical signal. Photometric detection, especially UV (including diode array and multi-wavelength UV detection) is by far the most frequently applied detection technique. The application of mass spectrometry (MS) detection in CE is attractive as it can provide structural information [44]. Hologram-based refractive index detection [45] and electrochemical detection [46,47] were also reported. Conductivity [41,48-50] and amperometric [51,52] detection has shown to have advantages for the analysis of both organic and inorganic compounds. [Pg.604]

As was mentioned previously, photometric detection is the most frequently applied detection technique. Most of the commercial CE-systems are equipped with at least a UV detector. Some compounds, such as low molecular weight organic and inorganic ions [57-60], do not produce a direct analytical signal. In such cases indirect detection, by indirect UV or fluorescence [59-64] is applied. Besides photometric detection, an application of indirect amperometric [65] detection was also reported. When the analytical signal results from a decrease in... [Pg.604]

Examples (a) Titration of Ph2+ ion with Cr2072 ion. The Figure 17.1 (c) corresponds to the amperometric titrations of Pb2+ and Cr2072- ion at an applied potential more than - 1.0 V when both these ions afford diffusion currents at this very potential and the end-point is duly signalled corresponding to a minimum in the curve. [Pg.255]


See other pages where Amperometric signal is mentioned: [Pg.325]    [Pg.325]    [Pg.663]    [Pg.57]    [Pg.79]    [Pg.172]    [Pg.184]    [Pg.357]    [Pg.468]    [Pg.27]    [Pg.67]    [Pg.267]    [Pg.364]    [Pg.195]    [Pg.145]    [Pg.149]    [Pg.156]    [Pg.162]    [Pg.192]    [Pg.247]    [Pg.250]    [Pg.261]    [Pg.268]    [Pg.269]    [Pg.310]    [Pg.370]    [Pg.379]    [Pg.441]    [Pg.582]    [Pg.582]    [Pg.434]    [Pg.145]    [Pg.409]    [Pg.2]    [Pg.144]    [Pg.628]    [Pg.279]    [Pg.107]    [Pg.162]    [Pg.19]    [Pg.168]    [Pg.23]    [Pg.291]    [Pg.291]   
See also in sourсe #XX -- [ Pg.97 , Pg.144 ]

See also in sourсe #XX -- [ Pg.97 , Pg.144 ]




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