The Research On Simultaneous Analysis Of Chloroacetic Acids, Three Herbicides And Eleven Anions In Water

The soluble herbicide could enter the drinking water by a variety of ways in agricultureproduction. After disinfected with chlorine, these herbicides may exist with disinfectionby-products，such as chloracetic acid. It is very harmful to human being. So the analysis ofherbicide residues and disinfection by-products is always the important and hot research.In this study, an ion chromatography method has been developed to simultaneouslydetermine three kinds of chloroacetic acids，picloram, glyphosate，bentazone and other ions suchas Cl^-, Br^-, SO₄^2-, ClO₃^-, ClO₄^-, BrO3-, PO4₃^-, NO₂^-, NO₃^-, acetate and formate. This method isfurther improved and the conclusions are as follows.The optimum analysis condition is achieved through changing the elution gradient and theanalytical column temperature with Dionex ICS-3000ion chromatograph, AS19anion analyticalcolumn, KOH gradient elution, suppressed conductivity detector. These seventeen anionscontaining organic and inorganic ions are successful separated and quantified in thirty-fiveminutes.The detection limit for all analytes are obtained between0.06μg/L （Cl-） and25.46μg/L（bentazone）, the correlation coefficients for all analytes are in the range of0.9940-1.0000, andthe relative standard deviations （RSD） ranges from0.20%to4.77%（n=6）.Interference experiment is designed to get the maximum concentration of some interferedanions which may affect the determination of trace analytes due to their high concentrations.Carbonate could be removed by OnGuard II H column. When the substrate concentrates wasidentified, the concentration of chlorate and sulfate should below100mg/L and50mg/Lcorrespondingly.78.3%-102.9%of the average recoveries for real samples spiked at500μg/Lare achieved. While the average recoveries for real samples spiked at100μg/L are lower thanthat.This study has discussed the determination of glyphosate by HPLC after pre-columnderivatization. Two standard curves of different ranges of concentration are got, each correlationcoefficient higher than0.99, and the detection limit is0.02mg/L. The RSD is between0.71%and5.29%（n=6）. Compared with HPLC method, IC method has advantages in sensitivity andprecision. Moreover it is easy to operate. The constant inorganic anions and trace organic components are simultaneously determinedwith this method. The pretreatment column in IC method is widely used, and the pretreatmentmethod is simple. This method is less time-consuming, highly sensitive, and totally meets therequirements of national drinking water for related substances, so it could be used to determinethese substances in actual water sample.