Determination of Picloram in Soil and Water by Reversed-Phase biquid Chromatography

:Picloram (4.amino-3,5,6-trichloropicolinic acid) is a ‘herbicide used for the control of woody and broadileaf plants and is marketed by the Dow Chemical .Companyi in formulations bearing the trade name Tordon@. Many agriculturally-impel-tant broadleaf ‘crops are susceptible lo very low levels of pi&ram lI@ab 1975: Thomson 1978). The potassium salt of picloram is very soluble in water and is slowly dcgraded by soil microorganisms (Hilton lY74). Thcrcforc, the environmental impact downstrcam ,from rhe treatmenl of forested arcas with pi&ram isof concern (Nary ef u/. 197’)). Methods of picloram analysis were reviewed (Zhemchuzhin 1978). Techniques utilizing pulse polarography (Whittaker and Osteryoung 1980) and high performance liquid chromatography (Skelly of al. 1976, Stevens 197’)). suitable for the analysis of commercial formulations without derivatiration, have been developed. Existing gas chromatographic (GC) methods for the analysis of picloram in water (Anon. 1968; Anon. 1973; Baur ef ol. 1972) and soil (Bjerke 1973; Ragab 1975) involve lengthy clean-up procedures followed by derivatization and analysis as the methyl ester. Studies designed to quantify the off-site movement of picloram resulted in large numbers of soil and water samples for analysis, and a rapid, economical. and reliable procedure was desirable. A method applicable to biological samples was necessary, which minimized the health and explosive hazards of diaromethanc used in the analysis by CC. This study was designed to establish a cleanup procedure for environmental soil and water samples sufficient LO permit the reversed-phase liquid chromatographic (RPLC) analysis of underivatired picloram with UV detection.