Garrido Frenich Antonia, Martínez Vidal José Luis, Fernández Moreno José Luis, Romero-González R
Research group Analytical Chemistry of Contaminants, Department of Analytical Chemistry, University of Almería, 04120 Almería, Spain.
J Chromatogr A. 2009 Jun 5;1216(23):4798-808. doi: 10.1016/j.chroma.2009.04.018. Epub 2009 Apr 15.
One of the major problems in quantitative analysis of pesticide residues in food samples by gas chromatography-tandem mass spectrometry (GC-MS/MS) is the enhancement or the suppression, of the target analyte signals in matrix extracts. Potentially positive samples, which had previously been identified by a rapid screening method, were quantified using standard addition to compensate matrix effects. As example we performed a systematic study on the application of the standard addition calibration (SAC) method for the determination of 12 pesticides (acephate, bromopropylate, chlorpyrifos, cypermethrin, diazinon, etrimfos, heptenophos, iprodione, methamidophos, procymidone, tetradifon, and triadimefon) in two matrices (cucumber and orange) in the range of initial concentrations of 10-200 microg kg(-1). The influence of some factors, such as the minimum number of standard additions used (single, two, three or four points calibration), as well as the known amount of analyte added to the sample, is evaluated in order to obtain reliable results. Accurate quantification is achieved when a single point SAC at 200 microg kg(-1) was used, obtaining for all the cases recoveries between 70 and 120%. The proposed analytical approach only needs two injections per sample (blank and spiked extracted sample) to determine the final concentration of pesticide in positive samples.
采用气相色谱 - 串联质谱法（GC-MS/MS）对食品样品中的农药残留进行定量分析时，一个主要问题是基质提取物中目标分析物信号的增强或抑制。先前通过快速筛查方法鉴定出的潜在阳性样品，采用标准加入法进行定量，以补偿基质效应。例如，我们对标准加入校准（SAC）方法在两种基质（黄瓜和橙子）中测定12种农药（乙酰甲胺磷、溴螨酯、毒死蜱、氯氰菊酯、二嗪农、乙嘧硫磷、庚烯磷、异菌脲、甲胺磷、腐霉利、三氯杀螨砜和三唑酮）的应用进行了系统研究，初始浓度范围为10 - 200 μg kg⁻¹。评估了一些因素的影响，如所用标准加入的最少点数（单点、两点、三点或四点校准）以及添加到样品中的已知分析物量，以获得可靠结果。当使用200 μg kg⁻¹的单点SAC时可实现准确的定量，所有情况下回收率在70%至120%之间。所提出的分析方法每个样品仅需两次进样（空白和加标提取样品）即可确定阳性样品中农药的最终浓度。
