Determination of 30 Pesticide Residues in 5 Kinds of Ginseng Health Food Ingredients by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS)Based on Modified QuEChERS-novel Porous Organic Polymers

In order to study the pesticide residues in ginseng health food ingredients, an analysis method for determination of 30 pesticide residues in Korean Red Ginseng, Salvia miltiorrhiza Bge, Scrophularia radix, Radix Codonopsis, and Pseudostellaria radix was established by combining the modified QuEChERS-novel porous organic polymers (POPs) purification with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were soaked in 1% ice acetic acid and extracted by acetonitrile, then purified by QuEChERS method without graphitized of carbon black. The purificated solutions were adsorbed and desorbed by novel porous organic polymers, concentrated by nitrogen stream and dissolved in 1 mL acetonitrile solution (volume ratio 6+4). The filtrates were separated by the Phenomenx Kinetex C₁₈ (100 mm×2.1 mm) chromatography column, using gradient elution of 0.1% formic acid aqueous solution containing 5 mmol/L ammonium formate-acetonitrile, determined by electrospray ionization, in positive ion switching dynamic multiple reaction monitoring mode, and quantified by the internal standard method. The results showed that the adsorption rate of 10 mg POPs materials self-made by the chemical method for 30 kinds of pesticides could reach more than 95%, and the desorption capacity reached 99% when eluted with acetonitrile-toluene (volume ratio 3+1) solution. The recoveries of 30 kinds of pesticides were increased to 5%~40% by modified QuEChERS-novel porous organic polymers purification. Method validation revealed that all 30 pesticides had good linearities in the range of 0.05~100 µg/kg, with correlation coefficients (r) higher than 0.990, and limits of detection (LOD, S/N=3) were 0.05~5.0 µg/kg. The average recoveries of 5 kinds of ginseng health food ingredients were ranged from 86.4% to 113.1%, with relative standard deviations (RSD, n=6) of 0.36%~8.74% at low, medium and high addition levels. While the limits of quantification (LOQ, S/N=10) were 0.10~15.0 µg/kg. This method has high recovery and high sensitivity, also can solve the issues of low pesticide recovery and strong matrix interference in ginseng health food ingredients by conventional QuEChERS pretreatment.