Cobalt phthalocyanine as a biomimetic catalyst in the amperometric quantification of dipyrone using FIA

Abstract

A biomimetic sensor for the determination of dipyrone was prepared by modifying carbon paste with cobalt phthalocyanine (CoPc), and used as an amperometric detector in a flow injection analysis (FIA) system. The results of cyclic voltammetry experiments suggested that CoPc behaved as a biomimetic catalyst in the electrocatalytic oxidation of dipyrone, which involved the transfer of one electron. The optimized FIA procedure employed a flow rate of 1.5 mL min(-1), a 75 μL sample loop, a 0.1 mol L(-1) phosphate buffer carrier solution at pH 7.0 and amperometric detection at a potential of 0.3 V vs. Ag/AgCl. Under these conditions, the proposed method showed a linear response for dipyrone concentrations in the range 5.0 × 10(-6)-6.3 × 10(-3) mol L(-1). Selectivity and interference studies were carried out in order to validate the system for use with pharmaceutical and environmental samples. In addition to being environmentally friendly, the proposed method is a sensitive and selective analytical tool for the determination of dipyrone.

Detection of Analgesics and Sedation Drugs in Whiskey Using Electrochemical Paper‐based Analytical Devices

“…While the performance of the ePADs is below other references , two advantages need to be highlighted. First, ePADs were prepared and used without any modification with nanomaterials or charge transfer mediators.…”

“…In general, the LOD values achieved in our study are higher than most of the data found in the literature. As can be seen in Table S3, the LODs reported in the literature for paracetamol, metamizole and midazolam ranged between 10 À5 À10 À10 mol L À1 [59-64], 10 À5 À10 À8 mol L À1 [64][65][66], and 10 À5 À10 À7 mol L À1 [67,68], respectively. On the other hand, the detectability levels obtained for metamizole and midazolam using ePADs were slightly better than those found in two reports.…”

“…While the performance of the ePADs is below other references [54][55][56][57][58][59][60][61][62][63][64][65][66][67][68], two advantages need to be highlighted. First, ePADs were prepared and used without any modification with nanomaterials or charge transfer medi- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 ators.…”

Preparation and Voltammetric Study of a Composite Titanium Phosphate/Nickel Hexacyanoferrate and Its Application in Dipyrone Determination

“…Many ways of anchoring compounds electrochemically active on the surface have been investigated in order to shorten the distance between the oxidation-reduction sites involved in electronic transfer reactions (Willner et al, 2000;Murray et al, 1984). In the literature, carbon paste electrodes modified with different matrices were used in the determination of dipyrone, such as an anionic exchange resin charged ions with hexacyanoferrate (III) (Marcolino Jr., 2007) and carbon paste modified with cobalt phthalocyanine (Boni et al, 2011).…”

“…Dipyrone (acid 1-phenyl-2,3-dimethyl-5-pyrazolones-4-methilaminometanossulfonico) (Pereira et al, 2002), also known as metamizole, which is an analgesic, antithermic and nonsteroidal antipyretic, widely used with proven efficiency in pharmaceutical formulations (Santos et al, 2009;Amaral et al, 2009;Lucchetti et al, 2011). Various methods are employed for their determination, such as amperometry (Boni et al, 2011), flame emission spectrometry (Lyra et al, 2011), spectrophotometry (Suarez et al, 2011), cyclic voltammetry (Teixeira et al, 2009), liquid chromatography mass spectrometry (Ojha et al, 2009), among others, given that the electrochemical methods are simpler and have a good efficiency.…”