Determination of Glyphosate in Water Samples by Alternating-Current Oscillopolarographic Titration

Abstract

This paper describes a novel, simple and sensitive method for the determination of glyphosate in water samples by alternating-current oscillopolarographic titration. Under an acidic condition, glyphosate can be transferred into a nitrosocompound by reacting with NaNO2. The titration end-point was obtained by the formation of a sharp cut in the oscillopolarographic with infinitesimal NaNO2 on double platinum electrodes. The results showed that glyphosate had an excellent linear relationship over the range of 7.16 × 10 -6 -4.14 × 10 -3 mol L -1 , the RSD of the proposed method was lower than 3%, and the spiked recoveries of three real water samples were in the range of 97.7 -100.2%.

Determinação espectrofotométrica por injeção em fluxo de glifosato em formulações comerciais de herbicidas

“…12 Há relatos de diversos métodos para a determinação de glifosato em matrizes diversas, incluindo as técnicas de cromatografia em camada delgada (TLC), 13 cromatografia de interação hidrofílica (HILIC), 14 cromatografia líquida de alta eficiência (HPLC), 10,15 cromatografia líquida com detecção por massas (LC-MS), 16 cromatografia gasosa (GC), 17 eletroforese capilar (CE), 7 espectrofotometria na região visível, 18,19 dentre outros. [20][21][22] Entretanto, nota-se a inexistência de descrição de trabalhos envolvendo a determinação de glifosato utilizando análise em fluxo.…”

“…12 Há relatos de diversos métodos para a determinação de glifosato em matrizes diversas, incluindo as técnicas de cromatografia em camada delgada (TLC), 13 cromatografia de interação hidrofílica (HILIC), 14 cromatografia líquida de alta eficiência (HPLC), 10,15 cromatografia líquida com detecção por massas (LC-MS), 16 cromatografia gasosa (GC), 17 eletroforese capilar (CE), 7 espectrofotometria na região visível, 18,19 dentre outros. [20][21][22] Entretanto, nota-se a inexistência de descrição de trabalhos envolvendo a determinação de glifosato utilizando análise em fluxo.Dentre os métodos propostos para a determinação de glifosato, as técnicas cromatográficas são frequentemente empregadas por apresentarem seletividade e sensibilidade. 15,16 A ausência de grupos cromóforos que absorvem no UV-Vis ou fluoróforos em sua estrutura dificulta a quantificação deste analito, havendo, portanto, a necessidade de aplicação de técnicas de derivatizações (pré-ou pós-coluna), nas determinações cromatográficas.…”

Determination of Glyphosate in Water Samples by Multi-pumping Flow System Coupled to a Liquid Waveguide Capillary Cell

“…6 Therefore, given the widespread use of glyphosate in agriculture, forestry, and home-use sectors, its monitoring and control is very important, especially in an aquatic environment. [7][8][9][10] Analytical methods have been reported for the quantitative determination of glyphosate in water and other environmental matrices; these methods are based on thin-layer chromatography, 11 capillary electrophoresis, 3 gas chromatography, 8,12,13 liquid chromatography, [14][15][16] luminescence, 17,18 visible spectrophotometry 5,19 or use electrochemical detections 4,7,20 or immunosensors. 21 Because the glyphosate molecule does not have chromophore or fluorophore groups in its structure; pre-or postcolumn derivatization has usually to be employed in liquid chromatographic determinations; however, direct detection at 195 nm is possible.…”

“…In general, the derivatization procedures require several stages to improve the resolution and selectivity, but their major drawbacks are a laborious clean-up procedure, a lower reproducibility and problems arising from the stability of the generated products. 7,8 Glyphosate is also a highly polar compound, resulting in additional difficulty in reversed-phase chromatographic separation procedures. However, there are effective solutions (e.g.…”

Direct Sensitive Spectrophotometric Determination of Glyphosate by Using Ninhydrin as a Chromogenic Reagent in Formulations and Environmental Water Samples

“…A literature survey reveals that so far, very few methods have been developed for the quantitative estimation of the presence of glyphosate, viz., gas-chromatography [3 -5], GC/MS [6] [7], liquid-chromatography [8], HPLC [9], electrophoresis [10] and current oscillopolarographic titration [11]. We now report the first direct, simple, rapid, and accurate spectrophotometric method for the determination of glyphosate residues thus meeting an ever increasing demand for the analysis of glyphosate in water samples.…”