Herrmann Susan S, Hajeb Parvaneh, Andersen Gitte, Poulsen Mette E
a National Food Institute , Technical University of Denmark , Søborg , Denmark.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2017 Nov;34(11):1948-1958. doi: 10.1080/19440049.2017.1339915. Epub 2017 Jul 3.
This study investigated the effects of particle size and milling temperature on the extraction efficiencies of pesticide residues from cereal flour. Samples of cereal grains (barley, oat, rye and wheat) were milled using a centrifugal mill with four different sieves (0.2, 1.0, 3.0 and 5.0 mm) or a knife mill both at room temperature and after freezing of the grain at -80°C overnight. The incurred pesticides in the test materials were extracted by the QuEChERS method and analysed by LC-MS/MS and GC-MS/MS. The particle size distribution for the milled samples was determined using a vibratory sieve shaker. Based on the pesticide levels recovered from each of the different millings and the corresponding particle size distributions, it was confirmed that smaller average particle sizes increase the extraction efficiency up to 31%, with all other factors equal. The cereals milled at room temperature produced lower pesticide extraction efficiencies compared with cereals milled when still frozen, especially for heat-sensitive pesticides. Furthermore, milling frozen grains was easier and resulted in more homogeneous samples with smaller relative particle sizes.
本研究调查了粒径和研磨温度对谷物粉中农药残留提取效率的影响。使用配有四种不同筛网（0.2、1.0、3.0和5.0毫米）的离心研磨机或刀式研磨机，在室温下以及将谷物在-80°C冷冻过夜后，对谷物（大麦、燕麦、黑麦和小麦）样品进行研磨。通过QuEChERS方法提取测试材料中所含的农药，并采用液相色谱-串联质谱法和气相色谱-串联质谱法进行分析。使用振动筛对研磨后的样品进行粒度分布测定。根据从每种不同研磨方式回收的农药水平以及相应的粒度分布，证实了在所有其他因素相同的情况下，较小的平均粒径可使提取效率提高31%。与冷冻时研磨的谷物相比，室温下研磨的谷物农药提取效率较低，尤其是对于热敏性农药。此外，研磨冷冻谷物更容易，并且能得到相对粒径更小、更均匀的样品。
