高效安全的敌草快和百草枯液相色谱分离分析技术

Analysis of Diquat and Paraquat by High Performance Liquid Chromatography

研究了KC lO4、KBF4和KPF6"离液试剂"的浓度及流动相组分对敌草快和百草枯分离的影响。优化后的实验条件是:20 mmol/L的KPF6,在pH=3的条件下用100%的水作为流动相,配合一根耐水性>95%水的反相柱。实验结果无论在保留值的控制、柱效和色谱峰的对称性各方面都优于传统的"离子对"方法。

Diquat and Paraquat are ionic compounds, and difficult to retain and resolve on silica-base RPHPLC columns. Consequently, the determination of diquat and paraquat is usually performed by ion-pairing reagents. In this study, a new RP-HPLC approach was established depending on the chaotropic effect, which is interpreted by the influence of some special inorganic additives to disrupt the analyte＇s solvation-desolvation equilibrium in the mobile phase. The effects of three ehaotropie agents （ KClO4, KBF4, KPF6 ） concentrations on the separation were studied. KPF6 is the most effective one and was used in the experiment practically. The separation conditions were optimized. In the system, 100% water （pH = 3） was used as mobile phase contai- ning 20 mmol/L KPF6 ; a reversed phase column which can be used throughout the entire range of aqueousorganic solvent mobile phase was preferable; the detection wavelength was selected 307 nm for diquat and 257 nm for paraquat. By comparing with traditional ion-pairing method, the retention value, separation efficiency, peak symmetry and ruggedness were all improved greatly in this approach.