Highly sensitive determination of paraquat and diquat in human blood with tetrabromophenolphthalein ethyl ester by ion-pair extraction/spectrophotometric method
K. Kato et al., Highly sensitive determination of paraquat and diquat in human blood with tetrabromophenolphthalein ethyl ester by ion-pair extraction/spectrophotometric method, ANAL SCI, 15(7), 1999, pp. 689-693