determination of trifluralin using adsorptive differential pulse voltammetric method

Abstract: herbicides are classified as carbamates, amides, diphenylethers, amino phosphates, and dinitroanilines. trifluralin (2,6-dinitro-n,n-dipropyl-4-trifluoromethyl-amine) is a benzene derivative belonging to the dinitroaniline family [1]. this toxin increases abortion, kidney and liver damage, allergies and decreases t lymphocyte count. trifluralin can also affect the function of the endocrine glands. in addition, due to its low solubility in water, it is one of the soil contaminants and causes several changes in the soil. in some reports, trifluralin has also caused air pollution, so it can be said that the identification of trifluralin is important [2]. trifluralin is detected mostly by chromatographic technology such as gas chromatography (gc) [3]. the electrochemical techniques, which are often simple and less expensive, have been also used to determine trifluralin [4]. in this project, an electrochemical method is used to measure this herbiside. to prepare the modified electrode, the pencil graphite electrode (pge) was firstly placed into a solution containing 2.4 mm l-cysteine and phosphate buffer solution (ph=7) and then poly l-cysteine/pencil graphite electrode (plc/pge) was fabricated using cyclic voltammetric technique with applying of 3 cycles over the potential range -0.4 to 1.6 v. after electrode preparation, the reduction current of trifluralin was measured in the presence of sodium dodecyl sulfate (sds) with applying adsorptive potential of -0.2 v during 200 sec. in order to achieve the best voltammetric response the electrode components and the other effective parameters were optimized and then trifluralin was determined using adsorptive differential puls voltammetric method. the linear dynamic range was investigated on the determination of trifluralin obtained as 0.25-100 μm. also, the effect of some cations, anions and environmental pollutions was investigated. finally, this method was successfully used for the determination of trifluralin in some real samples such as soil, water, tomatoes and oranges.