An accurate and stable nitrate-selective electrode for the in situ determination of nitrate in agricultural drainage waters

Abstract

A field evaluation of a novel nitrate-ion selective electrode (ISE) was undertaken by continuous immersion over a period of 5 months in agricultural drainage weirs. The nitrate sensor N,N,N-triallyl leucine betaine was covalently attached to polystyrene-block-polybutadiene-block-polystyrene (SBS) using a free radical initiated co-polymerisation, to produce a rubbery membrane which was incorporated into a commercially available electrode body. A measurement unit was constructed comprising the nitrate-ISEs, a reference electrode and a temperature probe connected through a pre-amplifier to a data-logger and battery supply. A temperature correction algorithm was developed to accomodate the temperature changes encountered in the drainage weirs. The nitrate results obtained with the ISEs at hourly intervals compared very favourably (R2 = 0.99) with those obtained with laboratory automated chemical determinations made on contemporaneous samples of drainage in a concentration range 0.47-16 ppm nitrate-N. The ISEs did not require re-calibration and no deterioration in performance or fouling of the membrane surface was observed over four months of deployment.

Influência do eletrólito na eletrodeposição de nanopartículas de Cu sobre eletrodo de diamante dopado com boro

“…21,22 Hoje, nitrato é considerado um agente poluidor de alto impacto ao meio ambiente devido ao uso indiscriminado de fertilizantes à base de nitrogênio, acarretando aumento de sua concentração em águas naturais. 23 De acordo com o limite recomendado pelas agências normativas, acima do limite aceitável, pode causar sérios danos à saúde humana e ao meio ambiente. 24,25 A modificação de eletrodos com NPs tem sido feita usando diferentes técnicas, tais como, decomposição térmica, 26 microemulsão, 27 e eletrodeposição.…”

Microfluidic Polymer Chip with an Embedded Ion-Selective Electrode Detector for Nitrate-Ion Assay in Environmental Samples

“…Nitrate ion-selective electrodes (NO3 --ISE) and nitrate ion-sensitive field effect transistors (NO3 --ISFETs) provide an attractive analytical method for the determination of nitrate ion, because the procedures are simple, and applied to colored and turbid samples. [15][16][17][18][19][20][21][22][23][24][25][26][27] The microfluidic chip technologies, such as integrated chemical analysis systems, micro total-analysis systems (μ-TAS) and "Lab-on-a-Chip", have attracted much attention because of a decreased use of reagents and lower sample volumes. However, the corresponding detection systems still remain large.…”

The Detection of Nitrate Using in-situ Copper Nanoparticle Deposition at a Boron Doped Diamond Electrode

“…2,11 Although the optimum method it is still expensive, time consuming and produces toxic waster products. 2 It is also limited by common interferences such as chloride and nitrite ions.…”

“…2,11 Although the optimum method it is still expensive, time consuming and produces toxic waster products. 2 It is also limited by common interferences such as chloride and nitrite ions. 1,12 Therefore research into different methods for the detection of nitrate is increasingly important.…”

“…Ion selective electrodes can be used to avoid the effects of common interferences. 1,2,5,11,12,35,[50][51][52][53][54][55][56][57][58][59][60][61][62][63] Some limits of detection using electrochemical methods are shown in Table 1.…”