Simultaneous determination of F~-、Cl~-、NO_3~-、PO_4~(3-)、SO_4~(2-)、BrO_3~-、Br~-、NO_2~- in tea by IC with hydrophobic column AS-15

Based on gradient elution method,ion chromatography(IC) with the hydrophobic column AS-15 was developed to simultaneously determine the content of inorganic anions(i.e.,F-,Cl-,NO3-,PO43-,SO42-,BrO3-,Br-and NO2-) in tea.Firstly,the tea powders were soaking in boiling water for 5 min at the ratio of tea to water as 1:50.Then,the powders were filtered out,and the filtrate was stabilized for 30 min.The prepared solution was treated by activated carbon cartridge,and the collected solution was filtered through a 0.20 μm filter membrane before injection.The results showed that the 8 inorganic anions were thoroughly separated,the contents of anions and peak areas gave a good linear relationship,the detection limit was less than 0.056 mg/L,and their recoveries in the range from 96.5% to 105.1%.The established method is robust,and it can be used for the routine determination of inorganic anions with sound repeatability.