Voltammetric determination of MCPA, 4-chloro-o-cresol and o-cresol in water using a modified carbon paste electrode

Abstract

Voltammetric method with use of modified carbon paste electrodes was applied to determining of MCPA herbicide, 4-chloro-o-cresol and o-cresol in water. All these compounds can be present in waste-water from production of MCPA or in river water. Carbon paste electrode was modified with mesoporous silica SBA-15 or powdered activated carbon Norit SX-2. The results showed that limit of detection for MCPA was 0.7 µmol L-1 and 1.3 µmol L-1 for Norit SX-2 and SBA-15, respectively. The smaller values of LOD for activated carbon were observed for other applied analytes. The electrode modified by this material used for determination of MCPA was better than electrodes in other works.

Potentiometric MIP-Modified Screen-Printed Cell for Phenoxy Herbicides Detection

“…Moving to phenoxy herbicides detection, the literature reports many chromatographic [ 10 , 11 , 12 , 13 , 14 ] and voltammetric [ 15 , 16 , 17 , 18 , 19 ] methods, but no potentiometric ones are described. Potentiometric and, more in general, all electrochemical techniques have several advantages compared to the classic ones: the instrumentation is less expensive, the time of analysis is low, the apparatus may be portable, the sensors can be used for in situ measurements, and the surface of the electrodes can be modified in order to obtain more specific and sensitive detections.…”

The Electrochemical Detection of 4-chloro-2-methylphenoxyacetic Acid (MCPA) Using a Simple Activated Glassy Carbon Electrode

“…Nevertheless, there are very few electrochemical-based sensors that have been developed and reported for the determination of MCPA. On searching the literature only three papers reported by Brett and co-workers 18,19 and Bialek et al 20 were found. In these studies, Brett and co-workers combined β-CD with multi-walled carbon nanotubes (MWCNTs) and this dispersion was then applied to a polyaniline modified GCE electrode to give PANI-β-CD/ MWCNT/GCE.…”

“…19 The authors attributed the enhanced oxidation peak currents observed for MCPA to both the MWCNTs and β-CD. Bialek et al 20 employed a carbon paste electrode modified with mesoporous silica or powdered activated carbon and found a linear range between 10 and 500 μM.…”

“…19 Interestingly, this reduction wave was not seen at the unmodified GCE electrode, while it is clearly evident at the activated GCE at relatively low concentrations of 0.14 mM for MCPA. Moreover, Bialek et al, 20 observed only a single irreversible oxidation wave, corresponding to the oxidation of MCPA, on cycling a modified carbon paste electrode between the potential limits of 0.0 and 1.5 V, suggesting that the emergence of this reduction wave is connected with the oxygenated species formed during the activation of the GCE.…”