Gas-liquid chromatographic determination of 3,6-dichloropicolinic acid in soils.
A gas-liquid chromatographic (GLC) method has been developed for the determination of the experimental herbicide 3,6-dichloropicolinic acid (Dowco 290) in soils. The method involves extraction of 1 g soil samples with 1N NaCl at approximately pH 7, methylation with diazomethane utilizing a microgenerator, and detection by electron capture GLC. Interferences are small, so that a cleanup step is not necessary even at the 6 ppb level. The procedure is rapid, requiring only 45 min/sample. Recoveries range from 84 to 94% at the 6-1000 ppb level with a minimum detectable limit of 6 ppb. Standard deviations for the percentage recovery values vary from 10.9 to 2.3 for the tested range of 6.7-670 ppb, respectively.
D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D006540:Herbicides / Q000032:analysis*; D008832:Microchemistry; D012987:Soil / Q000032:analysis*; D013997:Time Factors
D006540:Herbicides; D012987:Soil