Comparison of extraction methods for triazine herbicides in root crops using electrolytic conductivity detection

Characterization of Atrazine Accumulation by Excised Velvetleaf (Abutilon theophrasti) Roots

“…The combined supernatants were transferred to a separatory funnel, and distilled water was added to reduce the methanol concentration to 50% (v/v). Chloroform (CHCI 3) was added to the separatory funnel to give 15 ml CHCl 3 for each 100 ml of aqueous methanol (8,26). The separatory funnel was shaken for 5 min and the phases were allowed to separate for 12 h at 1.Q C. After removal of the CHCl 3 fraction, the aqueous -methanol phase was washed a second time with CHCI3, and the phases were allowed to separate for 3 h at 10 C. The CHCl3 phases were combined, reduced to the point of dryness under vacuum in a rotary evaporator at 30 C, and brought to 4.0 ml with anhydrous methanol.…”

Metribuzin residues in lentil following postemergence application

“…The green foliage, seed and straw samples were extracted and the extracts cleaned up using the procedures of Lawrence (1974) with some modification. Briefly, lentil tissue was extracted by blending with aqueous methanol (3:1 vol/vol methanol/water) and then filtered under reduced pressure.…”

“…Eight replicates were analyzed at each fortification level for each substrate. Lawrence (1974) had reported that several organic and aqueous organic solvent systems efficiently extracted metribuzin from the tissues of various root crops, and that increasing water content in the extraction solvent resulted in fewer co-extractive interferences during gas chromatographic analysis but also increased filtration times. Based on these observations, aqueous methanol (3:1 vol/vol methanol/water) was selected as the extraction solvent in the present study.…”

Determination of s-triazine herbicide residues in urine: analytical method development

“…The extraction of the s-triazine herbicides from plant materials involves maceration of the sample in a food blender with solvent, followed by filtration and partitioning. A number of different solvent systems have been employed for this work and were compared (Lawrence, 1974a). In addition, a low-temperature precipitation method has been described for the cleanup of plant residue samples (Lawrence and McLeod, 1974).…”

“…The methods all utilize the successive elution with solvents of increasing polarity to selectively elute the desired compounds. The supports most successfully used are alumina (Kahn and Purkayastha, 1975;Ramsteiner et al, 1974; Purkayastha and Cochrane, 1973;Young and Chu, 1973;Lawrence, 1974a;Schroeder et al, 1972), Florisil (Mestres et al, 1973;Westlake et al, 1973) and sodium bisulfate (Delley et al, 1967). Ion-exchange resins were extensively 0021-8561/79/1427-0740$01.00/0 © 1979 American Chemical Society used to separate radiolabeled s-triazines and metabolites (Bakke et al, 1967(Bakke et al, , 1971; Larson and Bakke, 1971) until it was shown that the procedure can quantitatively convert chlorinated s-triazines to their hydroxy analogues (Bakke et al, 1972).…”