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

Table 1

Analytical figures of merit for the SALLE technique combined with HPLC-DAD for multiclass pesticide residues under study.

Analyte	Linear range (ng/mL)	Regression equation	LOD (ng/mL)	LOQ (ng/mL)	r^2	^aRepeatability (RSD %, n = 6)		^aReproducibility (RSD%, n = 12)
THE	10–750	y = 0.116x + 2.3401	2.27	7.58	0.9993	^b2.02	^c3.38	^b5.56	^c7.77
CYZ	3–1000	y = 0.1776x + 2.7101	1.43	4.76	0.9997	3.54	2.05	6.57	4.52
CAR	2–750	y = 0.3345x + 2.8145	1.76	5.88	0.9992	5.50	5.13	7.32	5.13
ATZ	10–1000	y = 0.2883x + 6.8847	0.68	2.26	0.9994	3.11	1.97	8.13	6.57
MET	8–1500	y = 0.0384x + 1.8033	2.56	8.51	0.9991	4.40	4.04	7.52	6.65
AZO	5–1500	y = 0.1033x + 2.7038	2.05	6.84	0.9991	6.44	7.88	5.99	8.04
PRZ	3–1000	y = 0.4143x + 8.486	0.58	1.95	0.9982	2.88	5.13	7.67	7.59

^aValidated using a pasteurized milk sample one (PSM) sample. ^bLevel 1 : 10 μg/L for CAR; 15 μg/L for THE, CYZ, ATZ, and PRZ; 30 μg/L for AZO; 45 μg/L for MET. ^cLevel 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.