Glyphosate analysis using sensors and electromigration separation techniques as alternatives to gas or liquid chromatography

Abstract

Since its introduction in 1974, the herbicide glyphosate has experienced a tremendous increase in use, with about one million tons used annually today. This review focuses on sensors and electromigration separation techniques as alternatives to chromatographic methods for the analysis of glyphosate and its metabolite aminomethyl phosphonic acid. Even with the large number of studies published, glyphosate analysis remains challenging. With its polar and depending on pH even ionic functional groups lacking a chromophore, it is difficult to analyze with chromatographic techniques. Its analysis is mostly achieved after derivatization. Its purification from food and environmental samples inevitably results incoextraction of ionic matrix components, with a further impact on analysis derivatization. Its purification from food and environmental samples inevitably results in coextraction of ionic matrix components, with a further impact on analysis and also derivatization reactions. Its ability to form chelates with metal cations is another obstacle for precise quantification. Lastly, the low limits of detection required by legislation have to be met. These challenges preclude glyphosate from being analyzed together with many other pesticides in common multiresidue (chromatographic) methods. For better monitoring of glyphosate in environmental and food samples, further fast and robust methods are required. In this review, analytical methods are summarized and discussed from the perspective of biosensors and various formats of electromigration separation techniques, including modes such as capillary electrophoresis and micellar electrokinetic chromatography, combined with various detection techniques. These methods are critically discussed with regard to matrix tolerance, limits of detection reached, and selectivity.

Glyphosate Residues in Soil and Air: An Integrated Review

“…Capillary electrophoresis methods have been reported in recent years using detection systems such as contactless conductivity, electrochemiluminescence [100], and laser-induced fluorescence [101,102], as reviewed by Gauglitz et al [103]. Ion chromatography [104], electrochemical method, surface resonance-enhanced spectrometry, enzyme-linked immunosorbent assay also called ELISA methods [87], spectrophotometry [73,85], and fluorescent spectrometry [50,55,57,75,78,80,90,96] were also reported to detect GLY in current literatures.…”

Zirconia nanocomposites with carbon and iron(iii) oxide for voltammetric detection of sub-nanomolar levels of methyl parathion

“…A variety of analytical techniques like spectroscopy, [4][5][6] gas and liquid chromatography, [7][8][9] and gas chromatography coupled with mass spectrometry 10 have been developed which are accurate and sensitive. However, they suffer from disadvantages of being expensive, tedious and time consuming with lengthy sample preparation.…”

Glyphosate Determination by Coupling an Immuno-Magnetic Assay with Electrochemical Sensors

“…As discussed in a recent review paper by Gauglitz et al [ 14 ], despite the need for a massive monitoring programme, sensors and biosensors for fast and cheap glyphosate screening analysis, directly in the field, are still rare. The use of screening methods can permit the confirmatory method to be used only for positive findings, thus decreasing the number of samples to be analyzed and reducing the cost of the analysis.…”

“…Oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) substrate by HRP in the presence of H 2 O 2 generates an electroactive product, which is stable in acid solutions and can be easily determined by chronoamperometry. Glyphosate has been found in surface water [ 9 ], cereals, dairy, and other foods [ 14 ], and recently, traces of glyphosate have been also found in beer [ 25 ]. Thus, the optimized chronoamperometric immuno-assay has herein been used to analyze spiked beer samples.…”