Retention Time Verification Standard

2,2',3,4',5,5',6-Heptachloro-4-methoxybiphenyl, 1.2ml x 50ug/ml, nonane

Fensulfothion-oxon, 100 µg/ml, Acetonitrile, 5ml

Vamidothion, 100 µg/ml, Ethyl acetate, 5ml