DETERMINATION OF ANIONS IN INTERMEDIATES AND PRODUCTS OF THE PRODUCTION OF m-PHTHALIC ACID BY ION CHROMATOGRAPHY

Method of determination of 7 anions,including F-,Cl-,Br-,OAc-,NO-3,PO3-4 and SO2-4,by suppressed ion chromatography was proposed.Separation of the anions was performed by using the A-Supp.5-250 anion separation column (4 mm×50 mm) and a mixed solution of 2.8 mmol·L-1 Na2CO3 solution and 1.2 mmol·L-1 NaHCO3 solution was used as mobile phase,and the determination was done by conductivity detection.The 7 anions mentioned above were separated and determined within 20 min.Linear relationships between the peak area and concentration of the 7 anions were obtained with correlation coefficients in the range of 0.999 1 to 0.999 7,and RSD′s less than 1.3%.Detection limits (S/N=3) for the 7 anions obtained were 0.10,0.40,0.35,0.25,2.50,0.25 and 0.90 μg·L-1 in the above mentioned order.Values of recovery found were in the range from 98.2% to 100.3%.