Chromatography Forum

Hi folks,

Does anyone know how to analyze the concentration of fipronil (i.e., an insecticide with water solubility 1.9 mg/L) in solution? Also a method to analyze fipronil standard solution (fipronil comes in the form of powder).

I prefer of using RP-HPLC:)

Thank you in advanced.

Does anyone know how to analyze the concentration of fipronil (i.e., an insecticide with water solubility 1.9 mg/L) in solution? Also a method to analyze fipronil standard solution (fipronil comes in the form of powder).
I prefer of using RP-HPLC.

Have you actually even tried to do this assay? It's not especially involved.

Fipronil is readily soluble in organic solvents like methanol, and has UV absorbance about 280nm. We assay fipronil routinely, and at levels in finished products down to 10 ppm (yes 10ppm). Fipronil has essentially no acid-base character, so water and organic on RP-18 work fine for us, cannot divulge more for proprietary reasons. Consider purchasing pre-made fipronil standard solutions, as fipronil in concentrated form is darn toxic.

Hi, thank you for the information. This opens my knowledge, since as I know many use GC.

Would you mind if I can know the gradient program you use on RP-HPLC?

I am truly appreciate it. Thanks a lot:)

Hi, thank you for the information. This opens my knowledge, since as I know many use GC.

Regulatory agencies like EPA and FDA think they understand HPLC better than GC, so we typically try to use HPLC for regulated assays if possible.

Would you mind if I can know the gradient program you use on RP-HPLC?

Read my post. I didn't say that we use gradient. However, we have used both isocratic elution and gradient for fipronil, depending on the matrix. Start low organic and program your way up. Then modify. Then modify again. Have fun.