HPLC Method for Analysis of Paraquat and Diquat on BIST B+ Column

Separation type: Bridge Ion Separation Technology, or BIST™ by SIELC Technologies

HPLC Method for Analysis of Paraquat and Diquat on BIST B+ Column by SIELC Technologies
High Performance Liquid Chromatography (HPLC) Method for Analysis of Paraquat and Diquat

Paraquat and Diquat are two of the most popular herbicides on the market. With fairly similar structures and interactions with typical ion-exchange columns, they are usually extremely difficult to separate. Using SIELC’s newly introduced BIST™ method, Paraquat and Diquat, which protonate in water, can be retained on a positively-charged anion-exchange BIST™ B column. There are two keys to this retention method: 1) a multi-charged, negative buffer, such as Sulfuric acid (H2SO4), which acts as a bridge, linking the positively-charged herbicide analytes to the positively-charged column surface and 2) a mobile phase consisting mostly of organic solvent (such as MeCN) to minimize the formation of a solvation layer around the charged analytes. What allows these two compounds to be separated using BIST™ is the slight difference in charge position between the two analytes. Since the analytes interact so close to the surface, the minor difference in charge distribution is magnified and therefore significantly affects each analyte’s retention ability. Using this new and unique analysis method, Paraquat and Diquat can be retained and UV detected at 250 nm.


ColumnBIST™ B+, 4.6×150 mm, 5µm, 100A
Mobile PhaseMeCN – 70%
BufferH2SO4 – 0.2%
Flow Rate1.0 ml/min
DetectionUV 250 nm


Class of CompoundsHerbicides
Analyzing CompoundsParaquat, Diquat