Application of TLC for Confirmation and Screening of Pesticide Residues in Fruits, Vegetables, and Cereal Grains: Part 2. Repeatability and Reproducibility of Rf and MDQ Values

摘要: Abstract This paper illustrates the effect of major factors influencing reproducibility thin layer chromatography (TLC) separation and detection under largely differing environmental laboratory conditions. The optimum conditions for sensitivity was obtained on 20 × cm in retention factor (Rf) range 0.2–0.7 by applying sample spots 3–4 mm diameter at 2 from edge plate. rapidly decreased below Rf = 0.2. Above 0.2 within-laboratory 219 pesticides ethyl acetate silica gel elution system several laboratories typically 10%. among-laboratories average generally 12%. minimum detectable quantities (MDQ) pesticide residues were determined with nine methods. MDQ values varied depending mode detection. Bioassay methods enabled down to 0.1–10 ng, while 20–1...