Research And Application On Groundwater By Ion Chromatography Method In The Detection Of Fluoride, Chloride, Sulfate, Nitrate, Bromine And Iodine

This paper briefly analyzed the pollution status of groundwater resources and the main contaminating sources in our country, Several anion testing methods for water quality detection are listed, including F-, Cl-, SO42-, NO3-and trace amounts of Br", I". Compared with traditional testing methods, the ion chromatography method has the advantages of a good selectivity and a variety of ion detection at the same time. Thus, the ion chromatography method was chosen to test the normal content of F,Cl-, SO42-NO3-and trace amounts of Br", I" of groundwater, and as the main testing method for groundwater contamination survey.The method were established for normal content of F-,Cl-, SO42-, NO3-in groundwater by inhibition of conductance ion chromatography, instrument conditions: Flow system with equal concentration of30mmol/L NaOH and stable flow of1.4mL/min. Volume of sample loop:25.0μL. GC temperature:30℃. Current of conductivity detector:106mA. Time for whole process analyze pre sample:6min. Method Detection Limit:F-:0.012mg/L, Cl-:0.014mg/L, SO42-:0.074mg/L, NO3-:0.016mg/L. Linearity range:F-:0-10.0mg/L, Cl-:0-200mg/L, SO42-:0-200mg/L, NO3-:0-200mg/L. Resolution:Cl" and F":Rs=5.6, NO3-and SO42-:Rs=3.5. Ion correlation coefficient:F-r=0.9997、Cl-r=0.9999、SO42-r=0.9998、NO3-r=0.9999. Method Accuracy:take environmental reference sample204715as a working standard, the testing content of F-、Cl-、SO42-and NO3-is in the range of twice standard uncertainty which recommended. Recovery:F-93.9-104.8%、 Cl-95.2-103.7%、SO42-92.9-101.1%、NO3-93.0-95.8%. Precision:F-1.2%、Cl-0.66%、 SO42-0.86%、NO3-1.9%.An method for determination of Br-and I-in groundwater by ion chromatography with integrated amperometric detector was studied, instrument conditions:Flow system with equal concentration of50mmol/L NaOH and stable flow of1.5mL/min. Volume of sample loop:50.0μL. Working electrode:Ag. Reference electrode:Ag/AgCl. Time for whole process analyze pre sample:12min. Method Detection Limit:Br-:5.6μg/L, I":2.1μg/L. Linearity range:Br-:10.0-100μg/L, I-:10.0-100μg/L. Ion correlation coefficient:Br-:r=0.9998, I-:r=0.9997. Recovery: Br-:89.0-96.0%, I-:92.0-98.9%, Precision:Br-:1.0-3.0%, I-:1.0-2.9%; Moreover, compared the I" result of ion chromatography with the result of colorimetry, the detection limit of ion chromatography is much better than colorimetry, and the absolute value of relative deviation of both methods are less than that of method allowed.This paper established the ion chromatography method for detection of normal content of F", Cl-, SO42-, NO3-and trace amount of Br-、I-in groundwater, which can totally satisfied the requirement of quality control of lab groundwater detection.