Improved solid-phase enzyme immunoassay systems in the ppt range for atrazin in fresh water

A solid-phase enzyme immunoassay (EIA) in poylstyrene microtiter-plates was developed for the rapid determination of atrazin in fresh waters. The linear measuring range was between 1 and 2000 p mol atrazin per assay. Atrazin containing aqueous solutions could be directly assayed in a concentration range of 1.1 up to 2200 μg/1 (ppb). The sensitivity of this EIA variant was improved in two ways. Using polystyrene spheres as antibody carriers, a detection limit of 11 ng/1 (ppt) could be reached. If an affinity purified antiserum was applied, detection limits of 11 ng/1 (ppt) in case of microtiter-plates and 0.1 ng/1 (ppt) in case of polystyrene spheres as antibody carriers were obtained. The cross reactivity of other s-triazines in the atrazin EIA was tested.     

Analytical study of Asthart crude oil asphaltenes biodegradation

Various analyses of an asphaltenic fraction of Asthart crude oil enabled us to show that it was partially degraded by a marine mixed bacterial population with saturated hydrocarbons as cosubstrate. We also gave evidence of its strong biotransformation rate and tried to correlate its evolution with the nature of the produced fractions.     

Environmental chemicals and biomembranes 1. Nitrilotriacetic acid

Nitrilotriacetic acid (NTA) is readily taken up by yeast cells through simple diffusion and is metabolized. Concentrations of NTA in the millimolar range do not interfere with various membrane functions of yeast and bacteria.     

Rate of microbial degradation of high concentrations of α-hexachlorocyclohexane in soil under aerobic and anaerobic conditions

A case study was carried out to determine the bio-degradability of α-HCH in waste dumps polluted with HCH-isomers. Polluted soil was homogenized through a 2 mm sieve. The degradation of α-HCH (5300 mg kg^?1) occurred under anaerobic as well as under aerobic conditions; the concentration decreased in 20 weeks with 35% and 55% respectively. Addition of glucose, glutamic acid and peptone to the polluted soil hardly affected the degradation rate of α-HCH.