A modified QuEChERS protocol with a nitrogen-doped graphitized carbon derived from dicyandiamide sludge as a cleanup sorbent has been developed to determine 20 organochlorine pesticides in tomatoes using gas chromatography coupled to a triple-quadrupole mass analyzer. Compared with traditional QuEChERS adsorbents, N-doped graphitized carbon exhibited higher recoveries toward the target pesticides in tomatoes. And the modified protocol exhibited the advantages of environmental-friendly and low-cost. The use of dicyandiamide sludge to produce NGB as an adsorbent for QuEChERS opened up a new field for the comprehensive utilization of dicyandiamide waste. Under the optimum conditions, the modified method provided excellent linearity with correlation coefficient higher than 0.9980 and low limits of detection ranging from 0.001 to 0.1 μg/kg. The mean recoveries of the majority of pesticides in tomatoes ranged from 71.2 to 95.3% with relative standard deviation lower than 20%. Thus, the proposed protocol could be considered a good alternative for traditional QuEChERS method for pesticide analysis in agricultural vegetables.

中文翻译：

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基于N掺杂石墨化碳和GC-MS / MS的改良QuEChERS方法分析番茄中的有机氯农药

已经开发出一种改良的QuEChERS方案，使用源自双氰胺酰胺污泥的氮掺杂石墨化碳作为净化吸附剂，使用气相色谱仪与三重四极杆质量分析仪联用测定番茄中的20种有机氯农药。与传统的QuEChERS吸附剂相比，氮掺杂的石墨化碳对番茄中的目标农药具有更高的回收率。修改后的协议具有环保，低成本的优点。利用双氰胺污泥生产NGB作为QuEChERS的吸附剂，为双氰胺废物的综合利用开辟了一个新领域。在最佳条件下，改进的方法具有出色的线性，相关系数高于0.9980，检测限低至0.001至0.1μg/ kg。番茄中大多数农药的平均回收率在71.2％至95.3％之间，相对标准偏差低于20％。因此，该提议的方案可以被认为是用于农用蔬菜农药分析的传统QuEChERS方法的良好替代方案。