A New Method For Determination Of Ammonium Salt And Formaldehyde Content Based On Electrochemical Reduction Of Quinone

As the global economic development turns into the new normal,the human demand more and more from natural world,It caused some problems of ecology environment,especially air pollution and water pollution become serious.Therefore,a kind of method that can rapidly detect the air and water pollutant is very important.We this paper explored a new method that can rapidly and effectively detect the formaldehyde content in air and the ammonium salt content in water.In this paper,the electrochemical method was used to detect the contents of ammonium salt and formaldehyde by comparing the height of benzoquinone(Q)and the generation of acid.Because the acidity of formaldehyde and NH4+ is so weak that can not release enough proton to suppress the increase of the pH of the electrode surface.This paper,a relatively strong acid is produced by the reaction between ammonium salt and formaldehyde which to inhibits the pH of electrode surface.As a result,a new differential pulse peak is observed,which is independent of the concentration of benzoquinone,ammonium salt and formaldehyde.It only increases with the acid concentration,Consequently,the content can be determined more quickly and more accurately.According to the actual experiental situation,we utilized cyclic voltammetry to demonstrate the feasibility of the method and used differential pulse voltammetry method to detect ammonium salt and formaldehyde.It can be seen from the experimental conclusion that in the presence of a large number of protons in the aqueous solution,the p-benzoquinone reduction will first accept the protons,whereas the hydroquinone oxidation will release the proton.In non-buffered aqueous solutions,their redox potentials increase or decrease the pH of the electrode surface.The acid-releasing proton causes a new reduction peak at a relatively positive potential position.In addition,different pKa of acid,the peak position will be different,so the acid can be distinguished on the peak position to determine the strength of acid.Therefore,under neutral conditions,ammonium acetate and formaldehyde cannot provide protons lead to the emergence of new peaks.So we use the formaldehyde method of the product-strong acid which provides protons during the reduction of p-quinone.Based on the above principle,the content of ammonium salt and formaldehyde were quantitatively determined by measuring the acid content in aqueous solution.From the experimental data,it can be concluded that the acid concentration determines the current value corresponding to the positive potential peak,The standard curve of acid concentration and peak current can be drawn,and the concentration of ammonium salt and formaldehyde can be obtained to determine the content of pratical sample.Comparing with the traditional test method,the above measurement method is not only the sensitivity,but also without complex pretreatment,It provides a new way for the actual electrochemical determination of ammonium salts and formaldehyde.