Reduction of Matrix Effects in Liquid Chromatography-Electrospray Ionization-Mass Spectrometry by Dilution of the Sample Extracts: How Much Dilution is Needed?
Reduction of Matrix Effects in Liquid Chromatography-Electrospray Ionization-Mass Spectrometry by Dilution of the Sample Extracts: How Much Dilution is Needed?
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DOI：
10.1021/ac202661j
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发表时间：
2012-02-07
影响因子：
7.4
通讯作者：
Alder, Lutz
中科院分区：
文献类型：
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作者：
Stahnke, Helen;Kittlaus, Stefan;Alder, Lutz
在本研究中，研究了基质浓度与电喷雾电离抑制（基质效应）之间的关系。以 QuEChERS 提取物中农药的离子抑制为例。牛油果、红茶、橙子和芝麻菜这四种不同商品的无残留提取物分别添加了 39 种农药。对于所得的 156 种农药/基质组合中的许多组合，如果将 8 毫克等量样品（茶的情况：1.6 毫克）的共提取基质与未稀释的提取物一起注射，则观察到相当大的基质效应。在稀释 10 倍至 1000 倍时，测量了这些基质效应的减少情况。获得的结果表明基质效应与基质浓度（或稀释因子）的对数之间存在线性相关性，直到达到进一步稀释的零效应水平。使用对数方程可以表明，如果初始抑制为 25-40 倍，则提取物稀释可将离子抑制降低至 20% 以下。
In this study, the relationship between matrix concentration and suppression of electrospray ionization (matrix effects) was investigated. Ion suppression of pesticides present in QuEChERS extracts was used as an example. Residue-free extracts of four different commodities, avocado, black tea, orange, and rocket (arugula), were fortified with 39 pesticides each. For many of the resulting 156 pesticide/matrix combinations, considerable matrix effects were observed if the coextracted matrix of 8 mg of equivalent sample (in the case of tea: 1.6 mg) was injected with the undiluted extracts. The reduction of these matrix effects was measured at 10 levels of dilution up to 1000-fold. The results obtained indicate a linear correlation between matrix effects and the logarithm of matrix concentration (or dilution factor) until the zero-effect level of further dilution was reached. Using the logarithmic equations, it could be shown that a dilution of extracts by a factor of 25-40 reduces ion suppression to less than 20% if the initial suppression is