Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber

Table 3

The recovery and RSDs of the method.

Pesticides	Background/(ng mL^−1)	Add/(ng mL^−1)	Found/(ng mL^−1)	Recovery/(%)	RSD/(%)
Bifenthrin		5.00	6.29	126	9.9
		10.00	10.02	100	2.5
		50.00	47.8	95.6	2.1
Fenpropathrin	ND	5.00	5.60	112	12.1
		10.00	7.93	79.3	13.9
		50.00	45.6	91.2	6.2
Permethrin	ND	5.00	5.89	118	12.6
		10.00	10.27	103	4.8
		50.00	50.28	101	2.0
Cyfluthrin	ND	5.00	4.73	94.6	14.4
		10.00	9.75	97.6	4.1
		50.00	51.96	104	2.9
Cypermethrin	ND	5.00	5.61	112	7.1
		10.00	10.83	108	3.5
		50.00	49.80	99.6	5.7
Fenvalerate	ND	5.00	4.60	92.1	8.5
		10.00	10.25	102	11.5
		50.00	48.41	96.8	1.3
Deltamethrin	ND	5.00	5.53	110	10.6
		10.00	9.76	97.6	7.2
		50.00	50.96	102	6.6

Not detected.