Electrochemically synthesized polymers in molecular imprinting for chemical sensing

This critical review describes a class of polymers prepared by electrochemical polymerization that employs the concept of molecular imprinting for chemical sensing. The principal focus is on both conducting and nonconducting polymers prepared by electropolymerization of electroactive functional monomers, such as pristine and derivatized pyrrole, aminophenylboronic acid, thiophene, porphyrin, aniline, phenylenediamine, phenol, and thiophenol. A critical evaluation of the literature on electrosynthesized molecularly imprinted polymers (MIPs) applied as recognition elements of chemical sensors is presented. The aim of this review is to highlight recent achievements in analytical applications of these MIPs, including present strategies of determination of different analytes as well as identification and solutions for problems encountered

Amperometric sniffer based on electrodes supported on ion-exchangers for monitoring the state of turning rancid of lipids

A porous gold electrode supported on one face of an ion-exchange membrane, acting as a solid polymer electrolyte (SPE), is proposed as an amperometric sniffer for monitoring the aldehyde content in the headspace in equilibrium with lipid samples, in order to gain indication of their state of turning rancid It was used as a detector for a flow injection system in which aldehydes were injected, after preconcentration by solid phase microextraction on a SPME fiber from the gas phase standing above thermostated samples and subsequent desorption by heating. Repeatable (\ub1 4.5%) sharp peaks were detected over a wide linear concentration range (0.5-200 ppm). A detection limit of about 0.03 ppm was inferred for a signal-to-noise ratio of 3, referred to hexylaldehyde (used as prototype) dissolved in squalene or vegetable oils samples. This approach was applied to the determination of volatile aldehydes from some partially oxidized cereal oils and the results found were compared with both the corresponding peroxide values and their aldehyde content determined by a conventional spectrophotometric method

Continuous flow immunosensor for atrazine detection

The hapten atrazine was detected under continuous flow conditions using a micro-column which contained immobilized monoclonal antibodies (Ab) against atrazine and atrazine labeled with alkaline phosphatase (An*). The equilibrium of the antibody-hapten system, was achieved by a continuous flow of the tracer An* through the micro-column containing the immobilized antibodies. The activity of the tracer was monitored continuously, after the micro-column, by an amperometric detector using p-hydroquinone phosphate as substrate. When pulses of unlabeled atrazine (An) were added to the An* flowing continuously through the micro-column, An* bound to the antibody was displaced, with a consequent change of the detector signal. By this method atrazine concentrations in the range 9-180 mu g/l were monitored under conditions of continuous operation. Since the equilibrium condition for the system Ab-An* was continuously restored by the flow of An* through the micro-column the regeneration of the antibody was not required

Formic acid in gel (MAQS): considerations on the field trial results in Italy

Formic acid is an organic compound known for its miticide activity. To contrast some disadvantages of this active principle, such as the toxicity for the honey bees and to ensure the beekeepers safety in handling the product, a new formulation in gel has been produced by NOD Apiary Products Ltd, ensuring a slower and constant release of the formic acid. Mite Away Quick Strips\uae (MAQS\uae) is a commercial product in strips containing formic acid absorbed in a gel matrix. It is registered in Hawaii (2010), USA (2011) Canada (2012) and recently in UK (2013). In 2013, BASF started a mutual recognition procedure (MRP) for the registration of the product within several UE countries: Italy, France, Spain, Portugal, Germany, Greece, Romania, Bulgaria, Slovenia, Ireland. To verify the miticide efficacy and the toxicity for the honeybees, in 2011 MAQS\uae has been tested in Italy on 66 hives, placed in 3 different apiaries. Considering the lack of acaricide product registered for honey bees against varroa mite within UE, MAQS\uae could represents an interesting tool for beekeepers (organic beekeepers included), able to obtain high miticide efficacy in presence of brood and of supers. The results of the study will be presented and discussed