雾非雾
第6楼2013/06/14
Determination of insecticide monosultap residues in tomato and soil by capillary gas chromatography with flame photometric detection | monosultap; tomato and soil; residue analysis; gc-FPD-S | A residue analysis method for the determination of monosultap in soil and tomato was developed. Samples were extracted with deionized water, derivatized in a single-step procedure of hydrolysis under alkaline condition ( monosultap was converted to nereistoxin) and then cleanup by liquid-liquid partition. The tomato sample was further prepared by dispersive solid-phase extraction (dispersive-SPE) with primary secondary amine (PSA) as the sorbent. The residues were reconstituted in ethyl acetate and then determined by gas chromatography with a flame photometric detector (FPD-S). The results were further confirmed by gas chromatography-mass spectrometry (gc-MS). The limit of quantification was demonstrated to be as low as 0.01 mg/kg for the pesticide. The mean recoveries from soil and tomato ranged from 86.5 to 101.7 % with average relative standard deviation ( R. S. D) ranging from 0.49 to 10.0%. The method was applied to determine the fate of monosultap in soil and tomato. Data have shown that the disappearance rates on soil and tomato were described as pseudo-first-order kinetics and the half-life (t(1/2)) was less than 2 days.