Highly Sensitive Determination of Ethylenediaminetetraacetic Acid Using a Permanganate Chemiluminescence System Catalyzed by Gold Nanoparticles

A sensitive and selective chemiluminescence method was developed to determine ethylenediaminetetraacetic acid (EDTA) in water samples. It was observed that gold nanoparticles (AuNPs) catalyzed chemiluminescence (CL) reactions of permanganate-aldehydes which underwent an enhancement effect in the presence of iron(III) ions (Fe3+). This effect is more remarkable in the presence of EDTA, and a highly intensive CL emission is created in proportion to the EDTA concentration. These observations form the basis of the method for the high sensitive determination of EDTA in the 0.83 - 167 nmol L-1 concentration range, with a detection limit of 0.25 nmol L-1. The relative standard deviations for five repeated measurements of 5, 40 and 140 nmol L-1 EDTA were 1.14, 2.48 and 0.65%, respectively. The method has good selectivity toward EDTA, and there are no interferences from other ions. The offered method has good precision, and was satisfactorily used for the sensitive determination of EDTA in water samples.