A rapid sensitive method for the application of thin-layer chromatography to the detection and estimation of chlorinated organic pesticide residues has been developed. Compared to paper chromatography the method is faster, more sensitive, and in most cases more specific. Chlorinated pesticide residues were identified in extracts of various food products at concentrations as low as 1 part per billion; these results were verified by gas-liquid chromatography. Because of its simplicity, speed, and sensitivity, thin-layer chromatography is suitable as a rapid screening method or as a confirmatory method in conjunction with gas-liquid chromatography or other analytical methods for chlorinated pesticide residue analysis.

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The metabolic fate of the irrigation canal herbicide MAGNACIDE H [active ingredient, acrolein (2-propenal)] was studied using natural sediment and water under aerobic and anaerobic aquatic controlled laboratory conditions. Test systems were treated at the recommended application rate of 15 mg/L. Water, sediment, and volatile trap analyses were performed to determine the chemical degradation pattern of acrolein. The half-life of acrolein was approximately 1 day, resulting in the production of several metabolic products that were ephemeral in nature. Identifications included 3-hydroxypropanal, acrylic acid, allyl alcohol, propionic acid, propanol, and 3-hydroxypropionic acid. Characterization and identification of metabolites were achieved using three different modes of HPLC separation: ion exclusion, reversed-phase, and anion-exchange chromatography. Bound residues were minimal (6-18% of applied dose). A comparison of degradation products and pathways, which ultimately lead to the production of oxalic acid and CO2, under aerobic and anaerobic conditions is discussed.

Abstract-Acrolein, an aquatic herbicide, is applied as MAGNACIDE H herbicide directly into the water of irrigation canals at concentrations of 1 to 15 ppm. Two representative freshwater fish species, the bluegill sunfish (Lepomis macrochirus) and the channel catfish (Ictalurus punctatus), and two representative freshwater shellfish species, a unionacean clam (Elliptio complanata) and the northern crayfish (Orconectes virilis), were exposed separately to two applications of [ 14 C]acrolein, with 7 d between the two dosings. The nominal water concentrations were 0.02 and 0.1 ppm acrolein for fish and shellfish, respectively. Exposures were terminated 1 d after the second application. Metabolites were identified from the edible tissues of each test species; there was very little similarity in the metabolism of acrolein between them. The most notable observation was that acrolein was never detected in any of the tissues sampled. Glycidol, glycerol, 1,3-propanediol, and glyceric acid were the major metabolites found in the catfish, crayfish, bluegill, and clams, respectively. This study demonstrated that these test species, when exposed under static conditions to [ 14 C]acrolein, are able to metabolize the parent compound and its residues in their edible tissues. The metabolism of [ 14 C]acrolein is so rapid in the edible tissues of these species that neither acrolein nor its major oxidative and reductive metabolites, acrylic acid and allyl alcohol, respectively, were detected.

SUMMARYWe detected aromatic and aliphatic acids in root and seed exudates of aseptic cultures of pea, cotton and barley plants by thin-layer and gas-liquid chromatography. There were traces of p-hydroxybenzoic acid in the root and seed exudates of all three plant species. Acid hydrolysis of pea and barley seed exudates yielded p-hydroxybenzoic, and of cotton seed exudates yielded p-coumaric acid, as the predominant aromatic acid constituents of materials exuded by the germinating seeds. Lactic was the predominant aliphatic acid detected in pea and barley root exudates whereas malic acid was predominant in cotton exudates. With the exception of citric acid in peas, malic acid was the predominant acid found in pea, cotton and barley seed exudates. The germinating seed was responsible for a large portion of the total aliphatic and aromatic acid exudation of the seedling plant grown aseptically for 14 days.