On the estimate of blanks in differential pulse voltammetric techniques: application to detection limits evaluation as recommended by IUPAC

Blanc, Rosario; González‐Casado, Antonio; Navalón, Alberto; Vilchez, J. L.

doi:10.1016/s0003-2670(99)00569-3

Cited by 26 publications

(15 citation statements)

References 28 publications

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“…The percentage of inhibition, calculated as previously reported , exhibits a linear behaviour with the pesticide concentration, following the equation: %I = 3.75 + 1.10[carbaryl], with a correlation coefficient of 0.999 (n = 5). A limit of detection (LOD) of 1.4 lmol L À1 (0.28 mg kg À1 ) was determined using the 3r/slope ratio, where r is the standard deviation of the diffusion current values of 10 chronoamperograms of the blank, as recommended by IUPAC (Blanc, González-Casado, Navalón, & Vílchez, 2000;Currie, 1999). The same procedure was applied to the variation of methomyl concentration (Fig.…”

Section: Analytical Performance Of the Gc/mwcnt/pani/ache Biosensormentioning

confidence: 99%

Electrochemical detection of carbamate pesticides in fruit and vegetables with a biosensor based on acetylcholinesterase immobilised on a composite of polyaniline–carbon nanotubes

et al. 2012

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A sensitive electrochemical acetylcholinesterase (AChE) biosensor was successfully developed on polyaniline (PANI) and multi-walled carbon nanotubes (MWCNTs) core-shell modified glassy carbon electrode (GC), and used to detect carbamate pesticides in fruit and vegetables (apple, broccoli and cabbage). The pesticide biosensors were applied in the detection of carbaryl and methomyl pesticides in food samples using chronoamperometry (CA). The GC/MWCNT/PANI/AChE biosensor exhibited detection limits of 1.4 and 0.95μmolL(-1), respectively, for carbaryl and methomyl. These detection limits were below the allowable concentrations set by Brazilian regulation standards for the samples in which these pesticides were analysed. Reproducibility and repeatability values of 2.6% and 3.2%, respectively, were obtained in the conventional procedure. The proposed biosensor was successfully applied in the determination of carbamate pesticides in cabbage, broccoli and apple samples without any spiking procedure. The obtained results were in full agreement with those from the HPLC procedure.

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Section: Analytical Performance Of the Gc/mwcnt/pani/ache Biosensormentioning

confidence: 99%

Electrochemical detection of carbamate pesticides in fruit and vegetables with a biosensor based on acetylcholinesterase immobilised on a composite of polyaniline–carbon nanotubes

et al. 2012

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“…Imidacloprid residues in foods, agricultural, and environmental samples are usually analyzed by highperformance liquid chromatography (HPLC), gas chromatography with a mass spectrometer (GCMS) [1,7,8], and various electroanalytical [9,10] and fluorimetric [11,12] methods, as well as by enzyme-linked immunosorbent assays (ELISA) [13].…”

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confidence: 99%

Determination of the Insecticide Imidacloprid in Potato (Solanum tuberosum L.) and Onion (Allium cepa) by High-Performance Liquid Chromatography with Diode-Array Detection

et al. 2005

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A high-performance liquid chromatography (HPLC) method has been proposed for the determination of imidacloprid residues in fortified potato ( Solanum tuberosum L.) and onion ( Allium cepa ) and in treated potato and onion samples. Sample preparation consisted of dichloromethane extraction of imidacloprid from the plant material, followed by purification of the obtained onion extract on an LC-Florisil disposable cartridge. The obtained potato extracts were further analyzed without purification. The HPLC-diode-array-detection (DAD) method has been developed on reversed phase for separation of imidacloprid with isocratic elution with a mixture of 0.01 M phosphate buffer (pH 3.15) and acetonitrile (75 : 25, v/v). Spectral data obtained with DAD allow the identification of imidacloprid residue. Detector response showed a linear dynamic range from 0.0125 to 0.500 µ g/mL. Imidacloprid was recovered from fortified samples in a range of 94-99%. The within-day RSD of repeatability of the retention time of imidacloprid standard solution was less than 0.1% and of the obtained peak area less than 5%. For potato and onion samples, the limits of detection were 0.0075 and 0.0060 mg/kg and the limits of determination were 0.015 and 0.012 mg/kg, respectively.

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“…This procedure was not necessary when DPV was applied. This technique is considered a convenient method because of its limited influence of adsorption phenomena on recorded curves and thus excellent reproducibility, good sensibility, and selectivity, a wide range of linearity and the attainment of low quantification limit [43,48]. The oxidation curves recorded by DPV in the same solutions consist of one wellshaped peak (curve b in Fig.…”

Section: Voltammetry At Microelectrodesmentioning

confidence: 99%

Anodic oxidation of parabens in acetic acid–acetonitrile solutions

Michałkiewicz

2012

J Appl Electrochem

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The electrochemical properties of esters of p-hydroxybenzoic acid, called parabens, were investigated on a carbon fiber microelectrode and on a glassy carbon macroelectrode in glacial acetic acid containing 20 % acetonitrile (v/v) and sodium acetate as a supporting electrolyte. The anodic oxidation of parabens in this medium proceeds in a single stage giving well-shaped peaks or waves in the same potential region of above 1.0 V (vs. Ag/AgCl). The electrode process was characterized as being quasireversible, diffusion-controlled, and proceeds with the exchange of one electron and one proton. Phenoxyl radicals as products of the electrode process are chemically unstable and participate in the successive irreversible homogenous reactions resulting in electroinactive products (E q C i mechanism). Smaller oxidation potentials for parabens in comparison to such unsaturated fatty acids as oleic, linoleic, and linolenic ones indicate that these compounds can show antioxidative properties. Since parabens are often used as preservatives in many products, the results presented can be found useful in the determination of their total content in real samples.

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On the estimate of blanks in differential pulse voltammetric techniques: application to detection limits evaluation as recommended by IUPAC

Cited by 26 publications

References 28 publications

Electrochemical detection of carbamate pesticides in fruit and vegetables with a biosensor based on acetylcholinesterase immobilised on a composite of polyaniline–carbon nanotubes

Electrochemical detection of carbamate pesticides in fruit and vegetables with a biosensor based on acetylcholinesterase immobilised on a composite of polyaniline–carbon nanotubes

Determination of the Insecticide Imidacloprid in Potato (Solanum tuberosum L.) and Onion (Allium cepa) by High-Performance Liquid Chromatography with Diode-Array Detection

Anodic oxidation of parabens in acetic acid–acetonitrile solutions

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