Determination of Five Anions in Gentiana rigescens byUltrasonic Assisted Extraction-Ion Chromatography

Objective:A method was established for the determination of five inorganic anions(F-,Cl-,NO-2,NO-3,PO3-4) in Gentiana rigescens by ultrasonic assisted extraction-ion chromatography.Method:The effects of the sampling volume,eluent proportion,flow rate and column temperature on the separation of the anions were investigated.The effects of deionized water and NaOH(3.0 mmol·L-1) in different extraction time were also investigated.Result:Under the following chromatographic conditions:sampling volume of 100 μL,eluent of Na2CO3+NaHCO3(3.50 mmol·L-1+1.0 mmol·L-1),flow rate of 1.2 mL·min-1,column temperature of 30 ℃ for F-,Cl-,NO-2,NO-3 and PO3-4,the detection limits of 5 anions were 0.097 6-1.098 4 mg·L-1,the linear range of the calibration curves were 2-25 mg·L-1,2-20 mg·L-1,2-100 mg·L-1,10-55 mg·L-1 and 40-100 mg·L-1,the relative standard deviations(RSD) of the peak height were 0.98%,1.20%,0.77%,0.87%,2.26%,and the RSD of the peak width were 0.58%,1.27%,0.73%,0.92%,2.33%.With extraction for 30 min by NaOH(3.0 mmol·L-1),centrifuging with 10 000 r·min-1for 20 min,and filtration by 0.45 μm filter membrane,for F-,Cl-,NO-3 and PO3-4,the spike recovery were 110.38%,106.18%,96.47%,117.23%,whereas,the spike recovery of NO-2 was not detected.Conclusion:It is satisfied with using this method to determine the content of 5 anions in different parts of G.rigescens.