A Highly Selective Analytical Method Based on Salt-Assisted Liquid-Liquid Extraction for Trace-Level Enrichment of Multiclass Pesticide Residues in Cow Milk for Quantitative Liquid Chromatographic Analysis

<div>Typical chromatograms of blank (a), unspiked (b), and spiked (c) PSM milk samples at a concentration level 2 (100 μg/L for CAR; 130 μg/L for THE, CYZ, ATZ, and PRZ; 260 μg/L for AZO; 390 μg/L for MET). Extraction conditions: sample size, 5 mL; extraction solvent, acetonitrile; extraction solvent volume, 1000 μL; salt type, MgSO4; amount of MgSO4 added, 40% (m/v); extraction time, 0.5 min; pH of solution, 8.0; centrifugation speed, 4000 rpm for 5 min. Peaks identifications: 1, thiamethoxam; 2, cyanazine; 3, carbrayl; 4, atrazine; 5, methidathion; 6, azoxystrobin; 7, propazine.</div>

International Journal of Analytical Chemistry

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Figure 8

Figure 8: A Highly Selective Analytical Method Based on Salt-Assisted Liquid-Liquid Extraction for Trace-Level Enrichment of Multiclass Pesticide Residues in Cow Milk for Quantitative Liquid Chromatographic Analysis 

Figure 8 | A Highly Selective Analytical Method Based on Salt-Assisted Liquid-Liquid Extraction for Trace-Level Enrichment of Multiclass Pesticide Residues in Cow Milk for Quantitative Liquid Chromatographic Analysis 