Pesticide residue analyses in plant material by chromatographic methods: clean-up procedures and selective detectors Jozef Tekel Journal of Chromatography A olume 754, Issues 1-2, 22 November 1996, Pages 397-410 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TG8-3S9D74H-1X&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=bf46daa52330e09ae44a50b47c9c3633