Table 3.

Comparison of QuEChERS extractions for the determination of three residual herbicides in (A) brown rice, (B) soybean, (C) potato, (D) pepper, and (E) mandarin matrices.

Analyte		Spiking Level	Recovery ± RSD a (%)
			Original	AOAC	EN
(A)	Cyhalofop-butyl	LOQ	110.6 ± 8.4	71.2 ± 22.5	98.3 ± 4.2
		10 × LOQ	86.3 ± 7.7	127.3 ± 12.7	101.5 ± 1.5
	Quizalofop-ethyl	LOQ	76.8 ± 0.6	111.0 ± 7.6	96.5 ± 7.2
		10 × LOQ	99.0 ± 6.2	104.2 ± 0.6	94.4 ± 3.6
	Pyridate	LOQ	92.2 ± 7.9	121.9 ± 8.5	82.0 ± 8.7
		10 × LOQ	91.0 ± 4.3	86.8 ± 9.2	81.3 ± 1.1
(B)	Cyhalofop-butyl	LOQ	51.3 ± 19.9	72.3 ± 22.0	80.0 ± 12.2
		10 × LOQ	78.6 ± 2.2	101.5 ± 17.6	95.4 ± 12.5
	Quizalofop-ethyl	LOQ	85.5 ± 3.3	99.3 ± 2.7	86.3 ± 1.7
		10 × LOQ	85.2 ± 1.3	108.5 ± 7.9	102.4 ± 1.9
	Pyridate	LOQ	87.9 ± 0.4	85.5 ± 3.5	78.0 ± 4.5
		10 × LOQ	77.0 ± 3.5	86.8 ± 11.0	83.6 ± 0.7
(C)	Cyhalofop-butyl	LOQ	93.9 ± 1.7	115.3 ± 0.3	76.5 ± 9.2
		10 × LOQ	113.5 ± 6.9	124.6 ± 9.4	102.4 ± 13.2
	Quizalofop-ethyl	LOQ	90.5 ± 4.6	129.3 ± 1.0	104.2 ± 1.7
		10 × LOQ	92.4 ± 7.5	126.3 ± 8.5	106.9 ± 5.5
	Pyridate	LOQ	76.9 ± 2.0	128.1 ± 3.3	86.7 ± 10.4
		10 × LOQ	92.8 ± 6.5	110.5 ± 0.6	99.9 ± 1.7
(D)	Cyhalofop-butyl	LOQ	81.5 ± 37.7	27.8 ± 11.4	86.5 ± 2.6
		10 × LOQ	62.7 ± 14.1	100.9 ± 7.7	85.1 ± 4.9
	Quizalofop-ethyl	LOQ	68.4 ± 7.2	90.0 ± 6.9	93.3 ± 5.0
		10 × LOQ	75.9 ± 1.1	92.4 ± 3.3	91.7 ± 0.7
	Pyridate	LOQ	80.2 ± 11.2	87.3 ± 11.2	100.5 ± 1.9
		10 × LOQ	76.9 ± 3.4	97.0 ± 2.8	90.3 ± 4.8
(E)	Cyhalofop-butyl	LOQ	117.5 ± 14.0	95.8 ± 35.0	80.4 ± 17.3
		10 × LOQ	75.4 ± 0.8	91.0 ± 6.9	88.7 ± 9.0
	Quizalofop-ethyl	LOQ	81.1 ± 5.0	99.0 ± 4.6	82.2 ± 5.7
		10 × LOQ	94.0 ± 1.2	101.7 ± 7.0	94.0 ± 0.4
	Pyridate	LOQ	70.1 ± 7.1	78.4 ± 7.8	79.8 ± 5.2
		10 × LOQ	84.1 ± 1.2	81.2 ± 1.9	73.2 ± 2.1

^a Mean value of three measurements with relative standard deviation.