Analysis of 7 Dinitroaniline Residues in Complex Food Matrices by GC–NCI/MS

• Published in: Chromatographia Vol. 77; no. 5-6; pp. 493 - 499
• Main Authors: Xia, Guang-hui, Shen, Wei-jian, Wu, Bin, Lu, Hui-yuan, Zhang, Rui, Shen, Chong-yu, Yu, Ke-yao, Zhao, Zeng-yun, Liu, Han, Liu, Shu-qiang, Bian, Xiao-hong, Xu, Ji-yang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 2014; Springer Berlin Heidelberg
• Subjects: acetonitrile; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Chromatography; detection limit; food matrix; garlic; green onions; herbicide residues; ionization; isotopes; Laboratory Medicine; leeks; monitoring; olive oil; Original; Pharmacy; Proteomics; solid phase extraction; spectroscopy; Negative chemical ionization; Gas chromatography/mass spectrometry; Complex matrices; Dinitroanilines; QuEChERS; Isotope internal standard
• ISSN: 0009-5893; 1612-1112
• DOI: 10.1007/s10337-013-2618-0

A modified quick, easy, cheap, effective, rugged, and safe sample preparation method combined with gas chromatography–negative chemical ionization–mass spectrometry (GC–NCI/MS) has been developed for the determination of 7 dinitroaniline herbicide residues in complex matrices (garlic, olive oil, scallion, leek and chili). Dinitroaniline residues were extracted with hexane-saturated acetonitrile. After the cleanup with the dispersive solid-phase extraction, the extract was analyzed by GC–NCI/MS in selected ion monitoring mode. Two isotope internal standards (trifluralin-d₁₄and pendimethalin-d₅) were employed for quantification. Compared with electron ionization (EI) mode, the superiorities of NCI in sensitivity and selectivity were investigated. Limits of the detection of 7 dinitroanilines were in the range of 0.014–0.096 μg kg⁻¹, and there were no interfering peaks (unlike in EI) in the complex matrices. Recoveries of 7 dinitroanilines in five matrices at three spiked levels (10, 20 and 40 μg kg⁻¹) ranged from 61 to 126 % and the relative standard deviations were all below 12 %.